new equipment power conditioner or more powerful amp?

Agree, tweak the system setup and then the room. 

For $1-2k you could buy enough Blue Quantum Fuses, ECTs and HFTs to have your system performing on a level far beyond anything you could get from any new amp on the market. This stuff is seriously transforming, most of it you can try 30 days and return if you don't like it, and best of all you buy it once and use it everywhere forever from then on.

My 2 cents... improve your power by installing dedicated AC lines; cleaner power which will provide a lower noise floor.
Next would be room treatments, they don't have to be expensive. Then you'll hear the true sound of your current system.

Spend about $120 on a Furman power strip like this one:
https://amzn.to/2TkbFtj

And the rest on room acoustics.

GIK Acoustics and Michael Greene Audio are good places to start.

I 2nd-3rd-4th the ideas of room treatment and a dedicated line.
Check out ATS Acoustics online if your wish to DIY room treatments. Not difficult to make room absorption panels and relatively inexpensive.

Lots of info on both topics herein on this forum.

I believe in quality of power, not quantity. Not likely you need a new amp, considering power only.

I have a nice system also, but don't have dedicated lines, power conditioning, receptacles or room treatments (although I think my power and room are ok).  I don't have a particular area I can look at (listen to) and say it definitely needs improvement.  Not sure if you have done so already, but I am way behind the eight ball in terms of music streaming, internet radio, and the like.  I am waiting for an updated Sonos Connect to come out.  I believe the other streamers have surpassed the Sonos in fidelity, but I want to wait as I believe the Sonos is easiest to use.