Is it worth it?

seems to me that the VTL mono block is a better amplifier!  Once I listened to my speakers (Rockport Mira Monitors at the time) through my audio research amp & preamp, and then listened to a similarly priced Pass Labs amp and pre.  They both played nicely, but the tube gear sounded better to my ears (and my wife's), so I re-sold the Pass gear.

I am seeing that the VTL amps you have are pretty expensive as are the Pass amps that you are considering.  You speakers are far less expensive than these amps.  I understand that money is not everything in evaluating audio gear, but many people (myself included) feel that the speakers should take up a very significant portion of the system budget.  Of course there is nothing wrong with having a great amplifier, and Revel speakers have a great reputation...  But a $5k speaker and a $15k amplifier, I would probably go the other way around, and seek out a $15k speaker and a $5k amplifier.  I think you will get a far bigger bump in performance that way.

VTL plays very nicely with Wilson.  Just some food for thought.

Vtl sounds great, but built quality is not so great .
Failed power tubes often affect other circuit components 

"But a $5k speaker and a $15k amplifier, I would probably go the other way around, and seek out a $15k speaker and a $5k amplifier.  I think you will get a far bigger bump in performance that way."

+1! I can tell you from recent, personal experience ... your speakers are THE most critical electronic component of your system. 

You’ve got damn good speakers that punch way above their class. Unless there’s something you don’t like about them you’ll have to spend a lot more to exceed their overall build and SQ.

Just me, but I don’t believe these VTL’s are better than the Pass amps. If you could do an A/B comparison that would tell you clearly which would sound better in your system. 

But the Pass .8 amps are top of the food chain