I started with stock ZP90 into a Benchmark. Fell in love with the simplicity.
Upgraded Cullen modded upsampled Sonos to Benchmark. A nice bump in detail, but not sure if upsampling is their best option. Would like to have been able to compare this unit to a non-upsampling modded unit.
Moved to Empirical modded ZP90 to ultraclock re-clocker Pace-car to the Benchmark DAC-1. In my opinion from the road I've travelled above - Steve Nugent at Empirical is right. The holy grail seems to be to get jitter to a minimum and the brand of DAC becomes less a difference in the equation. Adding a battery power supply (the monolith) over the weekend drove this point home.
I do understand people complaining the Benchmark is 'analytica and cold'. I believe this is a jitter issue in the imput signal. Adding the reclocker to my system definately warmed the sound. It openned layers of sound that were hidden and now part of the entire presentation. The musical floor (silent, as well as quiet passages) is black, still and dead flat without hiss, hum or energy. Loud passages are big without edge.
My thought was a Berkeley Alpha might be my next component purchase. I'm thinking it is no longer necessary to change DACs.
I do wish I could try out high resolution files, but by not having that option has led me to push the envelop of red book CD sound. I am amazed how much information you can squeeze out of a file resolution we sometimes seem to take for granted.