Yes, I did the 600e upgrade last year. I think it's worth it (though some had commented in the past that the upgrade was 'subtle'). I found marked improvement in soundstaging, clarity (if you can imagine!) and on highs. I am running these via CAST Cables from EVO 707 (after upgrading from EVO 202 running on processor loop off of MC-12 v5 EQ). My source is Esoteric UX-1 Limited and speakers are Maxx3, with Opus MM2 speaker cables and PowerLink MM2X power cables for the amps. The two amps are each on a dedicated 20A line, the 707 and UX-1 Ltd are also on a 20 A dedicated line, though I use Shunyata Hydra as power conditioner for these two; both the 707 and the UX-1 Ltd also have PowerLink MM2 power cable (though 15A). Hope this helps. All three linies (in fact I have 6 such dedicated lines in all in my AV room) are all in the same phase, my meas voltage runs around 122V+/-2 or3V.