I've owned the kestral hotrods since december and believe just like any other speaker out there you have to work to get the best out of them. When standing the kestrals certainly sound different to me, though I don't believe the sound is better. This is in my room of course, not yours.
I've found that getting them a little further away from the listening position was a great help. This snapped the soundstage into focus - and just made everything sound more coherent, for lack of a better word. I haven't mearsured recently but I would guess the change was from 7.5 ft. to listening position to about 8.5 +,-. Kitch, I'll let you know. The trick, of course, is to also keep them far from the front wall(4ft in my case) to tame all the bass these things produce. In my experience that's what opens up their wonderful midrange. Maybe, this is what you're experiencing when you stand?
Dan, something does sound wrong. I originally had a similar complaint about the Kestrals and ultimatley discovered I had a broken connector off one tweeter - problem solved. Now, there is nothing lacking in the detail department. As far as amps go, the kestrals love tubes. Power, unless your bedroom is very,very large, shouldn't be an issue.
Kitch and Dan, good luck.