IMO Luxmans are a "delicate" sounding amp. Not bad, tons of detail, fantastic for female vocals, won't hurt you.
Don't have much experience with ARC other than a few in-store demo's. I find them to have more ooomph than a typical tube amp.
The Pass, Very good bass, excellent midrange a bit on the thicker, more musical side. Has the top end, but not as airy as the Luxman, and doesn't have that last bit of sparkle.
For my money, Pass if those are your three choices. Will hold it's resale best also, especially if you pick up a used or demo.
What speakers? What music?
