Benchmark AHB2 power amp impressions?

I had a chance to audition the AHB2 in my own system and later on also received the DAC2 to complete the audition (thanks to the local dealer for making this happen).  However this was maybe 9 months ago so please take into account that my observations are largely based on what I can recall.
The AHB2 is a very well built amp and its got a nice heft to it despite its small size, which is plus when moving it around in the rack.  Fit and finish is first class - no complaints there.  Since it was a new unit I gave it some 50 hours of burn in before critical listening
I drove it first with my CAT SL-1 preamp (AHB2 set on mid gain sounded bland so ran it on high gain).  It is indeed a QUIET amp - with the pre on mute, not a sound with my ears to the speakers (bookshelf Green Mountain Audio). To me the sound was very clean - almost too clean.  Abundant micro details and a black background though a little lean overall.  Overall it sound a little sterile for my taste - something like what you might expect to hear in a recording studio monitor I assume (I was reminded a little of my listening session with Genelec studio monitors which had a similar sound signature).  Pace and rhythm was very good, mids were very clean  but the overall presentation lacked something (the emotion?) which to my mind is that critical glue that binds all the elements of the recording and presents it as music.
Next up I drove it directly from the analog outputs of the DAC2 (DAC2 set to 0dB and AHB2 to low gain as is recommended).  This combination felt like a better match (even quieter and with more perceived drive) but the sonic signature didn't change much - and it was still a little lean and that sterility factor persisted - perhaps even more so.
I appreciate all the technology that has gone into making the AHB2 and the small form factor, great finish and substantial 190W @4ohms from a small chassis, But I wan't swayed enough by the sound to pull the trigger to purchase it.  Also, my own sense is that while the amp has three gain options to make it a suitable match for different pre/DACs etc, it was probably mostly conceived as a partner for the DAC2.
YMMV

I just got an AHB2 this past week. After using and moving heavy amps for a long time (Pass, McIntosh, etc) I decided I want a lighter, smaller amp. After reading reviews on the Benchmark, I decided to try it.

I’d echo many of jitterbug’s comments, though I don’t find it ‘sterile’. Perhaps because it’s so quiet and we tend to get used to other ‘noise’ in the music it seems that way, I don’t know.   I’ve been able to hear separation of instruments more clearly than ever before (at least to my auditory memory) and the level of detail is really something.   In familiar recordings I’m also hearing things I don’t recall hearing before. So far it’s been a real pleasure!

I’m using it with a Cambridge 851d as a preamp/dac and my current speakers are Harbeth C7-ES3’s. I currently stream via Apple TV to the Cambridge, and also use an Oppo 93 as a transport.

I plan on moving to a Benchmark DAC-2 HGC shortly as the Cambridge has developed a quite noticeable transformer hum.  

I Have owned a pair of AHB2 as monoblocks for a year, and they replaced a pair of Marantz MA9S2 with no regrets. Yes they are quiet and clear, more so than the Marantz.

It does not sound Sterile to me , but the partnering electronics have to match. In my system the Hegel P30 preamp sounds a little too aggressive on the AHB2, but the Cambridge 851E gives it a happy marriage. 

I have better amps but for the price, size, performance and convenience , the AHB2 is a great buy. I plan to keep them for a long time . 

Benchmark make great products - many of them "giant killers" for a good price. To be honest I don't care for the Marantz sound at all but I know many like the smoother more laid back or "natural" presentation they are known for.

If THD and S/N were all the buzz, we would never have things like tube amps, SETs, etc. where even 3% THD is not far from the norm, as well as s/n < 100dB.
It is no wonder that many audiophiles from the real world (you can find those only on various audio forums such as this one) assess this amp as "too clinical", "no emotion", etc. This is in sharp contrast to assessments of so called professional reviewers. Ask yourself why.
I'll start by asserting the following: neither Revel Ultima Salon 2 nor AHB2 that were used in most professional reviews are exceptional. Yes, you will find many praises for the two. But the MAJORITY of the real world audiophiles have already spoken. Nowadays, many people who bought Salon 2s regret their decision. MANY of them try to sell their speakers in very good condition on agon for less than half of the $22k msrp price, e.g. $10k, but are unable to. The word spread. The speakers were not worth $22k to begin with.
What about AHB2?
I'll answer by asking what about it's frequency range? What about slew rate? Rise time? It is widely known that as far as human ear is concerned both frequency range and slew rate are much more important than THD and other parameters (they are important, but not to the extent these other ones are). Ideally, the frequency range of an amplifier should be in the range 3MHz or more, but definitely more than 1MHz. Thus it is much better to design an amplifier with lower s/n and/or THD, and correspondingly higher frequency range and slew rate / rise time than vice versa. Only then you will get the so called "organic" sound, yet detailed and "you are there", "non fatigue" etc.