which $1k used floorstanders for 35wpc tubes?

It would be less of a gamble if you actually told us the name and model of your "35 wpc tube amp".

Also, since your amp and speakers are so mismatched, how do you know that you really love your amp? The NHTs are not bringing out the best of your amp and your amp is not truly showing what the NHTs do best.

I think I'm really sensitive to cabinet resonance (I returned a pair of Klipsches for this reason)

Guys,Try the Box test to hear the cow Moo artifacts
at 20 seconds in as CI sings the words 515 is just a train on your speakers this is what he is talking about.

http://www.songlyrics.com/chris-isaak/515-lyrics/
Cheers JohnnyR

With the Klipsch speakers, you may have heard the horn, not the box. I just went from Joseph Audio Rm25xl, which disappear in a room, to the Volti Alura,and it is hard to make it disappear, without careful setup. The horn does seem to pinpoint itself.

Also, the recording itself is Very important. On say The Woods Brothers "Magpie and the Dandelion", the individual guitar and mandolin are recorded directly from the left and right speakers. Not much you can do. Never noticed on the Joseph's but annoying on the Volti's. On well recorded music the band/ orchestra are in an expansive soundstage, and
the speakers boxes are gone.

Apologies to the OP for the off topic comments, I know it doesn't help with your search for speakers, but it may help someone else in the same boat.

Avett Brothers not Woods Brothers.

Rega RS1 or RS3 are VERY natural and as such are a prime choice for classical music.
Also, as they have minimal crossovers they are very easy to drive.Only speakesr mentioned I would put in their class are the Focals .