Price Paid:  $550.00 from eBay

Summary:
Having read lots of great things about the dna .5 I decided to try one. I now own a basic DNA 0.5. I am using the Marantz SACD player and McCormack TLC1 to drive the amp, and it drives a pair of Thiel CS1.2s. I use a paradigm active sub to help in the lower octaves. Nice mating to the speakers which I think is due to the room size and shape (usually add on subs create an annoyance to the sound, not a positive addition) The amp the DNA 0.5 replaced was a NAD C272.
Initial impression: from all the reviews and amplifier manual, I was suppossed to wait several hours for the amp to sound its best, but, being a tad impatient, I fired it up right away.
Sounded OK from a dead-cold state, but after about 1 hour things grew more refined. After a few days the improvements leveled out, but really, this amp needs to be turned on for a few days to sound its best. On to the show...
So the first thing that struck my friend and me was the purity and weight of the midrange. The NAD sounded like it was playing a clean musical signal, but the DNA 0.5 imparts emotion to the mids that I (to this day )can't believe is possible from a moderatly (to low) priced solid-state amp.
More on my setup: I have the Thiels about 7 feet center to center, 4 feet from the back wall and 3+ feet from the side walls. My listening spot is 9-10 feet from the front face of the Thiels. Room = 20x25x9.
Soundstage: the thiels completely disapper. On some tracks they look like they have nothing to do with the sound in the room. Completey de-coupled from the reproduction. Funny. The stage is a tad wider than the spacing of the speakers, and the front to back (and height) is more than adequate. On some recordings you think there are rear surround speakers. Also funny. Did not hear that with the NAD.
Sound Quality:
1)Bass- Despite the limitations of the little thiels, the bass clarity is great. That is, bass instruments are reproduced with clarity of pitch and weight. The sense of impact is quite good for this small setup. The overall fullness and warmth also notable.
Midrange: I am not going to compare it to tubes. Not necessary. The midrange is pure, clean, and extended. I am swept away on Diana Krall's warmth and weight. Natalie Merchant soothes me after a long day. Her voice wants me to say liquid, but i'm sick of that cliche...It sounds great...I throw in some smashing pumpkins and corgan's voice irradiates the room in an erie fashion, these qualities of sound are diminished with the NAD C272 I think..., I put in the SACD of BB King (reflections), crank it and I am amazed at the ease and BIG sound issued from the Thiels...BB's, ah, mature vibrato sounds spookily present in front of me. The band plays in the back like its part of the wall/yard...weird I tell myself..and this is with the STOCK DNA. The obsessed audio junkie in me screams wait till the Rev B or better upgrade...it gets better... but I soon return to earth an enjoy the pure music.
Highs:
Thiels have the reputation for sounding bright in some systems. Not so here. The NAD had good extension and detail, but the DNA 0.5 is a tad softer, perhaps a tiny bit sweeter, dare say I? Wonder what that RevA does...? The cymbals from a pure DSD SACD recording have that natural sheen you hear when in the presence of the real thing. Amazing. What will that plitron/diode combo possibly improve here?

The amp is an emotion engine... I will never part with it..You can have it from me when you pry it from my cold dead hands type of connection...speaking of connections I really wonder about those sweet looking WBT next gens...:)

...after the upgrade I will be replacing the beautiful Thiel CS1.2s with next generation and bigger brother Cs2.3s. Stay tuned to that plus upgraded DNA report on the 1.2s.

Love the amp. Highly recommended. None better at this price point.
Steve and Kris at SmC Audio are true gentlemen too.

Strengths:
Beautiful sound quality at peanuts price.
Powerful.
Reliable.
Customer service for an amp that was made in the early 90's.
Upgrades possible.

Weaknesses:
Zilch.
Makes me want to skip work and listen all day.

Similar Products Used:
NAD C272
Dynaco Stereo 70
Adcom GFA 555II, 585, 565.
Muse Model 100.
Theta Pro-Prime II
EAD T1000 Transport
Marantz SA8260
Aragon 24K
McCormack TLC-1
NAD 541i
Wire World Equinox
Kimber 8TC/TC
NHT Super Zeros

Price Paid:  $850.00 from used

Summary:
This is the Deluxe version, without any of the post-production modifications. It has been the cornerstone of my system for years. Every time I get upgrade fever and try to get rid of it, I find myself auditioning amps in the $2,000+ range to find significant improvement in the sound quality. They were a great value at full retail back in the day and are a tremendous bargain on the used market right now. I predict that in 10 years people are going to be talking wistfully about the DNA-0.5 in the way you hear old timers reminiscing about their classic McIntosh gear.

Strengths:
Warm, fluid, tube-like delivery. The rating of 100 wpc @ 8 ohms is conservative - it will play very loud without audible distortion.

Weaknesses:
None significant, although I wish it had balanced input jacks. I have noticed from reading various "for sale" posts over the years that there seems to be a tendency for the faceplate and heatsink fins to get dinged up.

Similar Products Used:
Bryston, Parasound, NAD, Adcom, Acurus, Linn, Classe

Price Paid:  $650.00

Summary:
Regretably I sold my McCormacks and went on a search for the perfect amplifier. I have come full circle. That is precisely what I did, I went in circles and wound up right back where I started, the McCormack amp. Nothing beats the McCormack DNA .5 Deluxe for pace, rythym, and drive, period. I am back to listening all my music and enjoying it even more! You will have to dig pretty deep in your pockets to beat this amp and then it may still not beat it for musical enjoyment and soundstaging. God bless Steve McCormacks's genius for these wonderful amplifiers. I have had McCormacks with the revision B and it will take what is already a superb amp to higher levels. Strongly recommend!

Strengths:
Huge soundstaging, musically involving. Quality engineering. A great bargain at its price point.

Weaknesses:
You must be joking.

Similar Products Used:
Conrad Johnson, Bryston, Aragon, Music Fidelity, B&K, McCormack DNA-1 Deluxe, and etc.

Price Paid:  $300.00 from www.hifimagasinet.co

Summary:
Believe all the hype. This is the real deal. Almost 10 years old and still better sounding than anything new at or near it's original price, let alone what you can pick one up for in the used market. I'll keep this forever. Crisp, clean, neutral, full, open soundstage and full spaciality, great separation, warm like tubes but nothing is overdone, never tiring, I can listen to this all day.

Strengths:
Everything about it.

Weaknesses:
If you have inferior musical source material, you'll hear it because this amp is accurate.

Similar Products Used:
Denon, Luxman, Arcam, and Dynaco amps--and this blew them all away.

Price Paid:  $750.00 from audiogon

Summary:
Picked up one of the last runs of the DNA 0.5 Deluxe for a steal, and after a couple months sent it off to SMC audio for their Rev 'C' upgrade ($400). The sound was smooth and neutral to begin with, drew no attention to itself. In Rev C guise the vocals are smoother and 'rounder', and the midrange overall seems faster and 'bloomier'. There is a greater sense of air and openness with better image localization. I had borrowed a VTL tube amp during the upgrade and the McCormack does everything the VTL did but better and faster. SMC is top-notch for customer service, doing some custom work at my request for a very fair fee, keeping me informed of progress, and being responsive to Q&A boith before and after the mods. Steve suggests a rev C 0.5 deluxe is a smidge more transparent than a DNA-125.
Rest of system:
Preamps: Sonic Frontiers Line 1, Adcom GFP-710, Headroom Max Reference, Creek OBH-12 passive
Sources: BelCanto DAC2 and Phono1, Magnum Dynalab FT101a, Nak DR-1, DR-10
Interconnect: Audioquest Viper, Coral, Emerald, others
Spkr Cable: Audioquest Bedrock
Spkrs: Modded Boston Acoustics A200 (!); other spkrs have been demoed with the DNA

Strengths:
Bargain price
Built like a tank
Superb after-sale service, with the cache of the designer tweaking your amp to your spec
Fresh circuit topology that's stood the test of time - and gets improved upon significantly for a moderate price
Excellent components esp for price point
Wonderful balance of smoothness, detail, presence, dynamics and power for a moderately priced ss amp

Weaknesses:
Bass impact is not Krell-like
Industrial-looking design appearance may not please the Stereophile poser set (I like its lack of high-end 'styling' pretentions)