When going to the Spa, @Mrs Poker Zombie strongly prefers Qua at Caesars. She's tried a few others but Qua wins every time.
PZ is right. Qua wins hands down. When he's been planning a trip to Vegas, my question is often "How far of a walk will that be to/from Qua?" Plus, at $400 for the spa, you can do a lot. Honestly, I've never walked out of there feeling I should have picked a different service. Let me know if your wife wants more info or heads up about going there.