Is It Worh Modding An Amp

It all depends on who is doing the modding and what their track record is. Modwright and Backert Labs both started modifying electronics. Perhaps people have heard of them? Ric at EVS mods mostly digital equipment. I'm sure there are others. You just have to use due diligence in your search.

I would not dismiss them out of hand. However, as @tablejockey pointed out, the PL gear is already full of premium parts. Not sure what you would gain with mods?

If you have money that is burning a hole in your pocket, why not check out some of the newest cheap class D amps. You may be surprised.

I see a portion of my post missing-

There are threads of PL owners swapping coupling caps and resistors. Just how much "improvement" is gained? I imagine it’s a YMMV thing?

Just how convincing the sound is coming out of your speakers-that's the sum of ALL parts. Recording/gear/room.

Sounds like it’s a coin toss at best that I’d really get good value out of upgrading. I guess if anyone is looking for a Primaluna Dialogue One hit me up. Thanks everybody! 

I suggest a look at the Mullard CV 4004 and then play with the Ultra-linear vs Triode.

When the U-L or Tetrode is discovered, then the 12 AU7 can be looked at for an exchange tube.   

I have had excellent results modding multiple amps, both solid state and tube.  Never once failed to get an improvement in sound.  What's the downside?  One downside is resale value.  However, I buy my equipment for my own sonic enjoyment so...