Will an Amp change improve my system ?

Don't have a lot of amp experience, just know that my Primaluna EVO300 pre with a PassLabs XA25 and 87dB speakers (PearlAcoustics Sibelius, REL T9) in similar size room works great for me. No problem with power, volume dial is at maybe 10 o'clock, at noon it gets painfully loud.

I demoed a half a dozen amps that all sounded the same from Nac, B&K, NAD, Sunfire, RGR and a couple others that made no difference. When I stepped up and tried a Krell product I was impressed at how much smoother music was. All those 200 wpc 'budget' amps sounded hard and unforgiving once I turned the volume up while the Krell, with the same power rating was able to play louder without the speakers shouting at me. 

Don't be afraid to listen to products above your budget even if only to hear what you're missing, or not.

For some of us, less is more.  I went from full on separates to a one piece system and couldn't be happier.  I sold all my McIntosh separates, and my Bluesound equipment and purchased a Linn MDSM all in one unit.  It has everything built into one unit.  The only other thing I bought to make it all work was an iPad to use as the interface.  I could use the Linn app on my Mac Mini to control it, but prefer the iPad.  If I am in the other room I can even use my phone to control all but the TT remotely. I have my TT and my Mac Mini (used as a music server) hooked to it.  I stream Qobuz, play any of my 8,000+ ripped songs, and my albums.  All without a lot of clutter of cables.  Everything but the TT is connected wireless over my mesh router.

Hegel and Harbeth have great sonic synergy, I'm thinking about getting the Hegel H400 + Harbeth m30.2 xd combo someday.

"I like my current system and wonder if an amp change would improve it significantly ?"

Probably not. If you are using the Schiit front end components and already are using the tube section on your Freya+, adding more tube amp effect or Class-A in lower-power amps won't likely add much to a system you already enjoy that has 140 WPC.