looking for opinions

I am considering pulling the trigger on my first experience with separates versus AV recievers. i have auditioned quicksilver, Rogue concerning Tubes and Krell, Pass for SS. I am considering the Pass xp-10 and XA-30 to drive my AudioPhysics Caldera II. I can get a 10 day return policy with RenoHiFI so that seems to be a good way to make sure i am happy with the matchup. Deal is very fair for a new 30.8 and used xp 10. I have not heard the matchup with these speakers but during some discussions with Nelson Pass he felt the 30.8 would do fine based on my listening area. It is a relatively small room with great wall treatment. Any thoughts on this particular matchup. the Caldera is listed at a 91 sensitivity so its obviously not as efficient as my previous Khorns and the overwhelming advice earlier on Agon was i needed to get better amplification.