Like anything audio, it comes down to opinion.
As for overpriced - oh I suspect most of it is!
No question Nelson voices his amps to have a house sound. I'm a fan, I have a 250.8. But I try to give some context. I want a live sound, I listen to rock, blues, reggae. I like a big sound, I do NOT like every single cymbal to come forward. But I do like a nice thick midrange, a very coherent sound and my bass a little "hot". Excitement however - that I do really, really love. I will sacrifice pinpoint imaging for a "live, big sound)
I've heard Dali's, but not my cup of tea so I can not comment there. Good speaker, not for me.
I think the ARC stuff actually punches pretty well for a tube amp. I heard them pushing some DynAudio Contour 30's and they were slamming in the bass.
Luxman - gorgeous old school stuff. I think the tone/loudness controls on the preamps are very useful for many.
The amps - way cool looking. Some of my favorite. I finally heard them just this past week at a friends house. Very nice amp, maybe a bit "airy" for my tastes. Compared to another he had (BAT) the bass wasn't quite as deep, powerful, or punchy. The highs were more defined and more delicate.
So, I think for the Dali's - either the ARC or Pass might help the excitement level.
(I have a Pass 250.8, XP12, and just acquired some Ohm Walsh 5000's, I really dig the combo but I'll admit its a bit different set-up than many "audiophiles" would use.).
Or, time to demo some speakers, what amp/pre/source do you have currently Roxy?