Noticed yesterday that Best Buy online had the 512gb SP2's available for order again -- am trying my luck with them, as the MS Online Store is out now and I've returned the first 2 they shipped with the 4200 CPU. Fingers crossed ;-)
It just arrived, lot #1404, and >yes<, the newer 4300 CPU -- finally! 3rd time is a charm I guess -- my consolation prize is the 6 years of 200gb SkyDrive coupons and 3 years of Skype
[UPDATE] -- Lot 1404 appears to be a good one. Aside from the CPU-refresh, the screen is brighter at even the lowest setting than my previous 2 -- might be a calibration thing, there's still a range of brightness settings, but it starts out higher and at the highest setting, is brighter than the others at their highest setting. This is with auto-brightness turned off.
Also, with the first 2 there was considerable screen bleeding around the edges. I really just noticed it when the device was booting and the screen was black. Both of my iPads had this, one much more than the other, so I've racked it up to the screen technology. The screen on my lot #1404 unit has virtually none of this around the edges.
When the kickstand is closed, it rests flush with the back of the Surface -- didn't notice it on the other 2 until I received the 3rd. When their kickstands are closed, there was a slight ridge where the kickstand met with the middle of the back.
Starting to seem like lot numbers are the equivalent of wine vintages ;-)