This unit is quite simple to use - there aren't that many features. That said, what it does, it does great. Editing the settings is super easy - just a few clearly labeled knobs and switches. Avalon provides a very thorough manual however, so if you read it and spend just a short time familiarizing yourself, you should have no problems in utilization.
The sound of the sources is captured in silky smooth, extremely accurate fidelity. This is a very transparent preamp, with a TON of gain available to use with very low noise. It doesn't really impart much of a flavor to the sound, but a lot of times you don't want that anyway. I love to use this pre on things like background vocals, acoustic instruments, and drum overheads (since it's two channel, you can use this for your stereo drum overheads quite easily). I also have been using it for DI bass guitar, and I have yet to get better bass guitar sounds than by DI'ing my bass through the AD2022. The low end is all there and is very controlled, but the presence you need to get the bass to still cut through is well represented too.
I have been using this preamp for about a year. I love the huge amount of gain you can get from it without it getting noisy, and how crystal clear the signals sound. It does seem to make them sound bigger as well. Bigger and wider, like there is more there to hear than you'd get if you used something like the Avalon 737. One caveat is that it has a somewhat annoying external power supply that you have to find space for. Really though, I can't think of hardly anything else negative to say about this great item. I have tried a variety of preamps, and while they all have their uses, this is the one I go to first when I am looking for a clean, accurate reproduction of an acoustic source. This is an expensive model, but after my first day of using, I had no regret whatsoever. It is well worth the money. I'd buy it again, and plan to in the future to get more channels of this thing!