On the general discussion about the Grad 1 / TPX2 performance, you'll realise I have vested interest, but nevertheless I'll share my experience.
I think Avondale power amps are excellent but can be bettered if you pay enough money - I had a pair of Avondale M2 monoblocks that were outperformed by their replacement Sanders Magtech - but this has a superb reputation and a list price of $5500. On the other hand, I never heard a pre-amp that outperformed the Grad1/TPX2, which is why I've used it for so long and upgraded everything else before not needing it. I can hear no audible improvement between using my Linn Klimax DSM/2 as a source into the Grad 1 and bypassing it and using the DSM pre-amp facility direct to the power amp (fortunately no detriment either), which shows just how transparent the Grad 1/TPX2 is. This definitely wasn't the case when auditioning a last spec Linn Klimax Kontrol (with a list price around £6K I think), which sounded constricted in comparison.