Benchmark ABH2 compared to Merrill Element Series and other ultra high end amps

I am sure that you will really enjoy the No. 16.  The differences between  the most 15.5's and the new 16 are the inclusion of newer low noise input transistors and an increase in the capacitance in the power supply from 200,000 microfarads in the 15.5 to 280,000 in the 16. I am fortunate to have a 15.5 which has the same lower noise input transistors used in the 16 but I am sure that the augmentation of the power supply will translate to improved performance.  Congratulations.

@soundhound Did you ever try the LA4 and AHB2 with the XLR cables that Benchmark recommends? Such as the low cost Benchmark Star Quad XLR's?

This is info I gathered from the Benchmark website regarding the XLR's to use..

Professional grade XLR, that support 24 dBu signal level and have CMRR specifications on balanced inputs?

I have much more expensive Audience XLR's compared to the Star Quad on my new DAC3B and HPA4 peamp and while it sounds great I want to hear the configuration Benchmark is suggesting is the best combo for their gear. I think Benchmark considers my Audience XLR's consumer grade gear.

BTW - I bought the HPA4 a few days ago and your comments  on how the LA4 sounded with the CODA 15.5 helped me get that instead of the 2 more expensive alternatives I was favoring. I love the HPA4. I am listening to headphones now late at night and it is great musical experience with the HPA4. Slowly starting to buy the gear I mentioned.

I have not tried the Benchmark XLR interconnects as I received advice from other users that they were decent but were bettered by a number of high quality interconnects. Benchmark amps and preamps do benefit from audiophile grade cables - including power cords, interconnects and speaker cables - although their literature does not acknowledge this observation.

The AHB2 is a special amp given the right load. It is not a good amp for ESLs. As soundhound mentioned ESL's drop their impedance as the frequency increases. Even mono strapped AHB2's  do not do well. However with an 8 ohm or higher, efficient speaker say like a Klipsch the little amps kick ass. They are priced lower because Benchmark makes professional equipment and the market is priced differently. They also really have their act together. I have their ADC and it is a little jewel. Beautifully constructed. I have no trouble recommending their equipment under the right circumstances. Don't let the price fool you. Benchmark stuff is as well made as anything out there. 
I have never been close to a Merrill amp. 
As far as ESLs go, and I have been using them for decades the JC 1 is very hard to beat. They make my stats thunder. Pass amps do very well.
The best may be Atma Sphere MA 2s.
 I am not an ML fan. Curving a panel is a silly idea and the man who designed them, Roger Sanders agrees. As far as Hybrid ESLs go Roger makes the best and they are very easy to live with. His amps also do a fine job driving ESLs. Sound Labs currently makes the best ESLs available by a fair margin. But, they are no compromise speakers and even the small ones will dominate a room. The big ones own the room. They are huge but boy are they special. They were using JC 1's to demo their speakers.