What's in your system? It's hard to recommend without knowing what else is in the chain. Also, what ideally do you want to keep the price under?
I've owned or auditioned every DAC on the list except the PS Audio Perfect Wave and the Bryston. I've heard good things about the perfect wave, but I've also experienced and heard of quality control issues with PS Audio gear now that their gear is made in China (not sure if the perfect wave is, and not trying to slag off China, but I went through 2 Power Plant Premiers before giving up on PS Audio, and a friend went through two of their phono stages).
I thought the Bel Canto was definitely better than the Cary and Benchmark. The Cary flattened the soundstage compared to the Bel Canto, and while it was a very nice sound (not harsh at all) I didn't feel it projected as accurate or large a soundstage as the Bel Canto. The Benchmark did a good job with soundstaging and was phenomenal with detail, but totally unforgiving in my system and made everything sound too analytical. The Bel Canto has the detail of the Benchmark, but is more natural sounding to me.
The Cambridge is a great DAC, especially for the money, but I felt bass was a little duller and the soundstage was more diffused than with the Bel Canto or Benchmark (instruments blurred together a little more).
I would second the recommendation of trying an MHDT. I have an MHDT Havana and the Bel Canto right now and the Havana, while not as precise as the Bel Canto (not in terms of detail, but in instruments placed in space) and somewhat rolled off on the lower end, is really fantastic for the money. I'm curious to try the Bryston myself, so may order one when I move to my new place and see how it does against the Bel Canto and the Havana.
