Gryphon vs Luxman vs Accuphase

Yes, I love my class A Luxman L-590AXII.  Before Luxman, I was using the Hegel H360 and was thinking about upgrading to the Gryphon Diablo 300.  I've heard the Diablo at the audio show and loved the sound.  But thanks to @greginnh for recommending the Luxman to me.  I took his advice and got the Luxman without any audition.  Now I don't have much desire to get the Diablo.  The Luxman was way better than the Hegel H360.  I've never heard the Accuphase, but I don't think you can go wrong with any of the 3 amps. 

I have not heard the 509.  I believe @greginnh has heard both the 509 and the 590, so he would know.  Since 509 is newer, it should theoretically be better than the 590, but again, 590 has the class A magic.  

I totally agree that the cables are very important to the system setup.  So is the system synergy.  In my system, I am getting effortless sound from my 590AXII and the rest of the setup.  I have a pair of Von Schweikert Endeavor E-3 Mk2 speakers.

stargazer3, Yes, I was referring to the sound quality.  Even though I've owned the Hegel H160 and H360, I did not use their internal DAC because I have a better DAC.  So, the most important thing to me is the sound quality, not the features.  I've also owned several other integrated amps (Vincent SV-236, Plinius Hautonga, Musical Fidelity Nu-Vista 800).  I do think Hegel amps are excellent, but Luxman 590 is just in a different league.  It just does everything better and sounds more refined than the H360.  I may eventually give Diablo 300 a try, but right now I am very satisfied with the Luxman.