Well, my opinion would be that the best amp YOU can afford is the best amp for your Stax. In my case, 353X is the most I'm likely to ever spend, so that is what I purchased. I would have LOVED to do Jim's SRX-Plus build for probably about the same cost, but I've never picked up a soldering iron in my life
I only have experience with 2 Stax headphones (SR-207 and L700), and 3 Stax amps (252S, SRM-1/Mk2 Pro, and 353X). And that's because I own them all, as like you, I have zero chance to audition anywhere near me. More than that, no meets I can travel to either. Sucks to work weekends
I can say that both 207 and L700 benefit to my ears as you climb the bottom 3 rungs of the amp ladder. I have no illusions that my 3 energisers *aren't* the bottom 3 rungs. And you know what? I'm completely happy with my experience
I took a hard look at my finances, and didn't see myself ever purchasing 007 or 009 (only talking about the phones themselves here). That restricted me to the Lambda series, and I took a leap of faith on L700 when I found the right "barely used" deal. Money talks, and I'm a sucker for a good price!
I then had to ask myself what the most I would be willing to spend on an amp was, and the answer was 353X. So you see, I'm happy because I already have my endgame setup! I actually have pretty much stopped even looking, though of course I still read and chat here. If money was no object........then hell yes, sign me up for 009 and DIY T2
But money *IS* an object, and in my case, an immovable object.
I postulate that my current L700/353X setup is better than what 99% of the world's population will hear in their lifetime. Better Stax systems cut further into that final 1%, but for myself I have found my stopping point and I've switched focus to my home theater ATM. I humbly submit that the $5K I just spent on subwoofers give me greater overall enjoyment than the step up to a $5K Stax amp (from my current setup) would. And I have to add that my headphone rig and home theater are independent systems in different rooms. One has to make choices!