I bought one of the early 2007 ES-339s, fat neck, vintage sunburst, last week and have been playing it over the long weekend. I am not a guitar player so much, but I need a break from violin, so I'm going to start working on improving my guitar skills.
This guitar has been highly modified, so I don't know about the "Memphis Wiring". I opened it up to look at the pickups to try to diagnose a dead e-string problem, and see that neither of the pickups are originals. They are (expensive) upgrades.
The finish has some checking, and there are nicks and dings, but I don't mind that. It stinks of cigarettes. It was a studio instrument at a large Hollywood recording studio, but although it has been played and modified, it stayed indoors all its life.
It arrived with a poor output on the high-e-string. Noting the B string sounded smooth and sweet, but no similar sound from the e-string through my amp. I tried changing the height of the pickups and filing new slots in the saddle bits to try to get the string centered over the pickup, but to no effect. I finally got a set of all nickel "Vintage Reissue" Gibson strings. Changing the strings made a huge difference. I called the seller and he said the strings on it when I bought it were "Ernie Ball Super Slinky", also nickel. I miked them and they read out 0.010, and I see that Super Slinkys are 0.009 or 0.011 so I don't know which they are, but at any rate, they did not work well with the pickups I was using. Your mileage may vary.
The only other changes I made were to change the intonation of the low E-string (Tune-o-matic makes that easy) and I put covers on the pickups (for looks only: they didn't seem to change the sound.)
It is just a joy to play. It is much easier to play than my Martin OM-28, and sounds nice with my Fisher Acoustic amp. I am feeding it to a red-eye preamp for convenience. I have been working out the fingering for Bach's Prelude to the 1st Cello Suite to guitar, and have tried a other tunes, as well as picking out tunes (Telstar, for example).