I've owned at least 5 different ARC preamps at one time or another and liked them all. You're going to get both refined and authoritive sound with the LS-25 MKII.I believe that's what the other poster's analogy between the two cars was conveying. The only reason I'm going to get rid of mine is to get a Ref 3.
ARC LS 17 vs LS 25 Mk II
I'm looking for a new preamp and am seriously thinking of going with Audio Research. Given that these two pieces are very close in price, which do you think I should go for, the newer 17 or the upper level 25 MkII which is a bit older? I'm looking for good air, soundstage, transparency and decay.