Looking for a change.

What kind of improvements are you looking for and what sound characteristics are most important to you?  Also, what’s your budget?

90 wpc is plenty of power for the speakers which are 91db efficient. If you want to make them sing introduce tube amp. If that doesn't float you boat then add a couple subs, preferably Rel to the mix 

I used to own a set of those. The classic combo is with Audio Research… like a Vsi75 or a Ref 75se amp. These would sound very different from what have now, rendering more realistically with mid range bloom and fleshed out nuance in the bass.. Tube alternatives: Conrad Johnson, VAC, and Cary. Alternatively Luxman would be a good choice with some tubed or not.

Here is a gross generality to think about. If you really like lots of details in your face and slam… then sticking with solid state and adding lots more power will tickle your fancy. However, if you want a more realistic sound (with all the details… just not in your face) and the bass more nuanced with great emotional content, then look to tubes like ARC…preamp and amp would be best. Or you can split the difference with Pass XA amp.

If you are unsure… go find a system run on tubes and have a listen. It is easy to think you want more details and slam until you hear a really good musical system. You already have a good set of speakers to head in that direction.

I am powering my current Sonus Faber (same sensitivity as yours) with an Audio Research REF 160… but in triode mode so it is only putting out 70wpc… sound great at at least twice the volume I would ever listen.

As expected the common theme is the Yamaha. I have a friend who is a Macintosh dealer and has been pushing me towards a Macintosh. Of course I could demo at home as long as it's in stock. He also has Prima Luna, which I know a few people mentioned tubes. I've also come across a Rotel RB 1590 which I would use as a external amp. I will begin seriously considering moving on from my Yammie, as the main power source, it has served me well.

@chasda take advantage of the opportunity to demo and listen to as many different manufacturers as possible.

My journey in audio has taken multiple steps and a Yamaha receiver was a significant step up during my journey.

What I've learned in my journey is manufacturers and amps sound different.  If you like them they sound good if you don't then they don't - but the reality is every manufacturer is forced to make compromises and the end result is a specific characteristic.

I have owned McIntosh and thorough enjoyed my units with a tube pre and SS amp.  When I decided to upgrade I was able to listen to Audio Research, Rogue, Moon, Boulder and McIntosh.  I noticed my tastes changed and ended up switching for McIntosh.  Enjoy the process and what every you decided - the person to satisfy is the one looking back at you in the mirror!