i have the late 2012 model(2.5ghz 128ssd), i was wandering if i should exchange it for the early 2013 model with 2.6ghz, 256ssd
what i dont get is the change in the backplate and the SSD, is the backplate better? is the SSD more reliable? (im still within 14 days to return)
most importantly which screen does it uses in early 2013 model? samsung or lg?
I was faced with the same decision when I purchased my 13" retina MBP this past week and I opted for the 2013 2.6GHz 256GB SSD version. The primary reason was for the larger SSD although I could have gotten that size SSD in a late 2012 model with the 2.5GHz processor through mail-order for less money. I was also worried about how easy it would be to exchange if there was a defect, and that prompted the decision to go for the newer version from an Apple store. It's a premium purchase and felt the customer service from them was worth the extra cost. So far I haven't experienced any disappointment. Whether or not the changes in the newer model make any difference, I can't be certain, but I can say I'm happy with what I have right now and I'm glad that if any problems do arise in the next 14 days, I can easily switch it for another computer.
You asked about which manufacturer made the screen, but I wasn't able to find a method for determining that. There is a terminal command that can be used on the 15" model but it doesn't work on the 13". My SSD is a samsung according to the system report.
Which ever screen I have, it's gorgeous. Regarding the lag, I tried several of the sites that many people say demonstrate the problem, but it wasn't noticeable, until I later saw some jerking when I scrolled through my tumblr account. There you can scroll endlessly as it loads older and older content. When I tried the same on WebKit it was noticeably smoother, although whether I shift to using it as my default browser instead, I'm not sure. This is after upgrading to the latest release of ML OSX 10.8.3.
Hope this was helpful.