Upgrade for Totem Mani 2

What is your budget?

What is your price range?  Type of music listened to most often?  Keep in mind it's not always efficiency of a speaker. It's how they work wiht said amp.  That Pass amp is plenty powerful to rock some top good speakers.  It's mostly class A if I recall right?  It's also got a ton of current and that's more important that watt's.

I have a friend who owns Vandersteen Treo's CT and also owns your same amp with matching Pass amp and loves them together.  He listens to a lot of rock and he listen's loudly.  I ran my Treo's using an NAD integrated amp that isn't nearly as high current at your amp for a couple of weeks and the sound was pretty darn awesome.  I didn't expect that as I have a large room.

Having had several different Totem speakers, though not Mani 2, I would suggest taking a listen to Dyaudio. Similar to Totem but better to me. Totems I had could get a tad harsh sounding with certain recordings. No issue with my Dyns. Plus your Pass amp will pair very well with Dyns. My current speakers are Dynaudio Contour C20. Knowing the Mani 2 has great lows I don't think you'll miss much of that from the C20. 

A pair of Vandersteen 2's are in the 2500 range if I recall correctly.  The fact that they are time and phase correct will stop the smearing that you will get with a non time and phase aligned speaker.  It's very noticeable on acoustic music and also jazz.  Having a full range speaker like the 2's are also nice for the lower bass notes I have found.  Dynaudio makes a nice speaker also.  I auditioned many of them when I was looking and my buddy has their 60k ones.  I just feel for many they appreciate the tonality, micro and macro dynamics of the Vandersteen's.  Go listen to both and see which one you like best.  They are very differently tuned, so I'm sure you will like one or the other better.  Both good solid companies that stand behind their gear too.