I have never heard a high powered amp of any sort that was capable of delivering great dynamic contrast at low volumes, detail without an artificial edge, and a truly enveloping soundstage like a very low powered SET amp (10, 45, 2a3 and 300b). But, these kinds of amps have quite limited applications. Where a little more power is needed (anything well over 10 watts) I would look next to an OTL. These amps can deliver most of what a SET can deliver, and in a very critical area (dynamics, liveliness) they are pretty much unmatched. There are some matching issues as well with OTLs, so I cannot say whether any particular one would work well with your Vandersteens. I would certainly give something like the 30 watt Atmasphere a trial.
This is a rough generalization, but, for me, the least appealing kind of amp is a high-powered tube amp with oodles of pentode or tetrode tubes in pushpull operation. A lot of these sound hard and artificially edgy.
I find that many of the better, high powered solid state amps no longer sound particularly grainy, and while none have quite the natural attack (leading edge of the note) of a SET, they are not nearly as edgy as they once were. What I find is that they sound somehow dull, flat and uninvolving unless the volume is cranked up a bit. I've heard some systems (not my own) with certain high-powered solid state amps that sounded reasonably good, but these amps were extremely expensive (Soulution, MBL, and D'Agostino).
I have heard, and liked, some lower powered solid state amps. I think the lower powered Ayre amps sound reasonably good. I particularly liked the First Watt J2 that I had in my system for a week (borrowed from a friend). This 25 watt amp was quite natural sounding once it warmed up. I would not trade in my SET amp for the J2, but, then again, the J2 costs less than one tenth of my SET amp. I would bet that its 25 watts would be enough for the Vandersteens at anything but extremely high volume.
If you want to test whether an amp can deliver enough juice for demanding situations, my suggestion is to find large scale choral works. For some reason, systems will distort (voices become muddled and fuzzy) at what subjectively does not seem to be that extreme a volume level with such works (look for something like Rachmaninov's "Vespers").