I own four (maybe five) tube preamps and maybe two solid state preamps. Over the years, I've owned about six SS preamps, and all but one just didn't cut it. For me the worst an Adcom I gave away to keep from tossing it out in the back yard! The best one was an Accuphase, and even it was just not quite there. The Adcom just hurt my ears!
Thru the years I've owned a few tube preamps, and everyone of them have the same characteristic. The they tend to remove the glare and graininess that so many tube amps produce (my current solid state amps don't). The sound is somewhat more fluid, and seems to have a better flow. Much nicer to listen to. My bottom grade tube preamp is a midline ASL that has been re-capped with better tubes. It's better than all the solid state preamps I've own (well lets say 75% better). Right now I'm using a Quicksilver that is in dire need of a major tune up. Yet is better than the other stuff. I have a factory rebuilt Conrad Johnson that has about six to seven hundred hours on it, and like that "CJ house sound!" I also have an Odyssey tube preamp. An absolute steal at the price tag, but honestly is not my favorite. The sound is better than the other two for sure, but lacks some features I want. Mine was the second one built, and they say the newer ones are even better. (we're going to find out next year). The Quicksilver and the Odyssey are very neutral sounding, but the latter is a little more detailed in sound.
What would fix the deal for me would be the Odyssey with six inputs and a tape loop (tape I & tape 2). Guess I want to run to much stuff thru my system!
gary