I brought the Adcom home about a year ago for an extensive in-house trial (a week), and compared it to several other units at the same time.
It is indeed "incredibly transparent". The soundstage and clarity is amazing, especially in passive mode. It also has a great array of features, too often missing in high-end "less is more" equipment. I really like the full-featured mono switch, the home theatre pass-through, the full-function remote (not just volume) with motorized volume control, etc.
I found it, in the end, *too* transparent. I was afraid it would be too harsh for extended listening (it was bright in my system). Poorly-recorded CDs (re-issues of old rock 'n roll) sounded truly awful (this is what people mean when they say you will start listening to different music when you upgrade your system!) And many recordings seemed to be a little less "musical" ("rythmic"?) -- less "sway your hips" effect.
I ended up with the Classe CP-35. While not as well-regarded, in my system it is a little warmer and more musical. Regarding your requirements, it has a full-featured remote and is solid state, but has nothing in the way of home theatre pass-through. An optional internal phono stage is available (a good thing for me). It lacks a headphone jack; I plan to add a headphone amp in the future.
Obviously, your listening room and the rest of your equipment will have a big effect. I have a mass-market CD player (due for upgrade), British speakers, and a somewhat bright, large room (I'm working on carpets lately). So your mileage may vary!
I personally believe the speakers, room (including speaker placement, carpeting, etc), and pre-amp are the most important components. You're in a tough position because you're looking to replace more than one of these, which makes in-home demos tougher.
This is a case where working with a good dealer makes sense (if you aren't already). The ideal scenario would be to take your amps and music in to the dealer, and work with them to find a pre-amp and speaker combo that you like. Then ask to demo the winners in your home. Try again if things don't sound as good in your home as they did in the store. Buy the pre-amp now, and the speakers later (from the helpful dealer, of course). Listen to CD players while you are it.
No dealer has everything you are considering, but a good dealer will carry several lines of pre-amps and speakers that you are interested in, and that will likely be enough. The opportunity to really evaluate the equipment is more important than getting what has been reviewed as the "best" but doesn't actually sound that great in your house.
This sounds like a lot to ask from a dealer, but the one I bought my pre-amp and amp from did all this for me (I hauled my speakers in), and sold me demo unit (pre-amp) and last years model (amp) at a discount. I actually demoed gear from three dealers in my home ("my" dealer didn't sell the Adcom or any integrateds, and I wanted to hear those).
Well, this is probably information you have already thought about. In any case, I wish you the best. Take the time to enjoy the looking!
- Eric