Thanks for the info on IR/ghost. There is another *massive* thread on here about it dating back to the first retina displays and right up to the present. And another useful thread on "macrumours" http://forums.macrumors.com/showthread.php?t=1662379&page=8
Still deciding between this 13" and a samsung book 9 plus (haswell, HD screen) at the moment. Having read this long long thread and all the other threads and reviews on ghosting etc. I'm still having a hard time deciding whether or not to buy the macbook. From these reviews forums I've read, among various other things, the following "stuff" (and as usual it's hard to decipher the truth, from the speculation, from the wild guesses, etc etc):
Image retention/ghosting is an inherent issue in display technology no matter what (with technical reports available from tech. companies eg. NEC etc.).
"Burn in" is a similar but different issue (which isn't relevant to the retinas).
There are LOTS of reports of image retention on previous retina models (seemed to be a pretty major issue)
There are quite a few reports on new 13" retinas (late 2013) ghosting.
There is a standard "checkerboard test" http://www.marco.org/rmbp-irtest.html
The test gives positives on both new and old systems, as reported by users
The level of ghosting varies a lot.. some get it after 1 minute of the test.. some after the full 10 minutes.. some only on parts of the screen.. some not at all!
Reports are that it shows up only after a certain use period (depending on the particular case in question) e.g. a few weeks.. or a number of months
The LG displays were the main culprits on previous generation retina macbooks (as they came with both LG and Samsung made screens)
Samsungs don't ghost but have a variety of other problems and according to some people the samsung doesn't look as good (brightness etc etc)
According to the macrumours forum the people posting in that forum aren't sure if the 13" late 2013 has samsung or LG displays, or both such as in previous models
Apple has a standard test program that they run on your computer themselves if necessary with a "postive" result meaning they replace the screen as a matter of standard procedure (I believe this is different to the "checkerboard" test from marco.org)
Some people get positive results from the "checkerboard" test i.e. they can see ghosting but don't notice it in daily/normal use
People buying 13" retina pros now still have screens manufactured in late 2012
So yer as usual when you delve into these issues on forums there is a lot of vastly varied information and user experiences to sift through. And it's hard to guage the overall problem when really, even if a forum has thousands and thousands of views, you can't really tell how widespread the problem is compared to total production etc.
Warranty should solve but I guess it's an inconvenience I would personally prefer not to have to worry aboutand with a significant number of reports in forums etc. it makes it a hard decision to buy one or go with another windows laptop of which there are some perfectly suitable ones for my purposes out there.
Thanks again Oli.