I have two Macs, a 2010 27 imac I've upgraded to a 512 SSD and 12Gb RAM, and a 2011 MB Air 4Gb RAM and an OWC 256Gb SSD. MY usage model doesn't involve anything processor or GPU intensive, but I do run some specialized programs and have 2-3 dozen things open at once. The imac is my main machine, say 65-70% of the time, but when traveling (about 6 weeks each summer, plus courses, daily library/archive research), I'm on the Air. Financially, I can update one of these, but can't decide which to prioritize. The Air beachballs a lot, runs the fan a lot (even with all the tweaking and optimizing I do) and probably *needs* to be replaced more whereas the iMac still runs fine. However, the Air is not the main machine, plus, I was hoping for a price drop and the tiered battery upgrade on the MBP refresh, so I'm inclined to wait for next year on that. I'm going to be doing a crap ton of reading on the imac in the next year, so a Retina screen would be really nice, but the Air needs it more. I'd go for another 27 imac with a 512 SSD and upgrade the ram myself, vs. a 13 MBP, ideally the TB for the higher specs. If this were you, what would you do?