I have seen a lot of people complaining about the 13" retina on here but just wanted to redress the balance a little. One caveat before I start though, I picked up a brand new 256Gb model at a big saving - otherwise I would find it very hard to justify the retail price. Now, I switched from a late 2011 cMBP with 8GB ram and 240GB SSD which I was very happy with but in some instances, wished it had a higher resolution screen. The retina 13" seemed like the ideal laptop for me and so I managed to sort out a good deal for my upgrade. The retina is noticeably smaller but the keyboard & track pad remain identical so usability remains the same. Performance is great, this thing flies through tasks and while not a big step up from my previous model, I have noticed improved video encoding times using Handbrake for example. If this was the kind of thing I did day in, day out then I would have gone for a quad core 15" model but otherwise the 13" is certainly fast enough. Heat dissipation - I'm thinking the retina runs as hot under load as the cMBP, possibly even very slightly hotter but this is hard to discern given there is less surface area. One thing which very much improved though is the fan design, the older model under load could get quite noisy. Even under load, I can barely hear the retina model making a noise - it took around 20 mins of a Handbrake encode and putting my ear next to the bottom of the screen before I could hear any fan noise. This was both very unexpected and very welcome! Image retention - to date I haven't encountered any but then I haven't been looking for it either - just using the laptop for normal use. Some simple things that would have triggered IR in older screens that I have seen have so far not shown anything up in this model. UI lag - something I was aware of and a little concerned about even though I knew it wouldn't be a deal breaker. I have to say, I see it the first time the dock animates into place or when I first call up mission control but it really is minimal and any subsequent actions are buttery smooth. This is nowhere near as bad as I was expecting. Finally the screen. I'm a big fan of the retina displays but I primarily use my iPad for the likes of reading and browsing so could easily get by without it. There are occasions in the past though that I could have used a little more UI space - be it certain websites or working with an image in Photoshop. The ability to scale the UI to a higher resolution is fantastic and really makes this finally the laptop I have been wanting. I still stick with the best for retina (1280x800) resolution for most tasks but having the flexibility to jump into a higher resolution for image editing or iMovie is just plain superb! If I just used the MBP as a hub for things like downloading, iTunes etc. and didn't do much in the way of reading or photo editing then the cMBP would have sufficed but the ability to scale the UI really makes this form factor a much more usable proposition for the likes of technical apps.