Have Luxman 509x. Considering Pass Labs INT-250 or Dan D’Agostino Progression Integrated

@denon1 , thanks for the post. As an L-590AX owner, your comments are interesting.

Thanks Denon1. I would be looking forward to your experience with the 509z.

I will have to burn 509z for many hours. The mistake of some owners (I was there too many times) to make conclusions before sufficient burn. It costed me a lot of money to ignore burn in significance, system synergy, isolation and room acoustics.

@denon1 "It costed me a lot of money to ignore burn in significance, system synergy, isolation and room acoustics."

100% agree. I like to look for low-hours gear put back on the market by people prematurely looking to move to other components as a result of this situation. Same happens with new speakers as well, by not letting everything settle in.

WORSE:

And, to your point, I was a show a 3.5 years ago where there was imo a really bad setup of Pass Labs amps and speakers. Omg it just sounded horrible to me, woah, compared to what I’d heard prior times in other setups. It was all new gear too, and break-in seemed to be limited too. The speaker pairing just did not work, at all. The cabling seemed limited, and could not say much about the room setup. Just weird.

Felt really bad for the presenters, and lack of care paid attention to the results. A total miss on that day imo. It clearly showed that good matching and setup can make a real difference. People did not stay long in that room, flowing in/out.

BETTER:

Then hearing the same amplifier(s) with better matching speakers and appropriate cabling, in a much better room setup, a very different and more enjoyable result.

If anybody interested, I got luxman 509z last week.  I traded 507z towards it. The 507z is already build like a tank, but to me the 509z build is another level up. The speaker terminals, top cover , side panels - better quality. But what surprised me the volume knob and input selector knobs are also on a different level- smother and more precise. 
i got mine brand new and now it has about 30 hours on it, I already  can say that it’s even more naturally sounding with even blacker backgrounds than 507z. My personal opinion - when burned for 300-400 it will exceed 507z on all levels. 
With every solid state integrated I personally owned (pass int-250, gryphon 300, plinius hiato, accuphase E-800, gamut 150, luxman 509x, luxman 590axii, mark levinson 580.5) i always herd some hardness at the beginning. With 509z - not a case. This 509z is  a real gem. Granted I learned a lot for the last few years about system synergy, cables, isolation - so it’s all contributing to the sound.
I am just a customer and not affiliated with luxman in anyway.