Also consider with the 21.5" you're never be able to access the RAM so will have to pay Apple and still be limited to just 16Gb. The slower video card, the 5400rpm HDD which is limited to just 1Tb. So to make the most of the 21.5" you'll be paying around $2000 for it with Fusion and 16Gb of Apple RAM. That's the starting point of the 27".[/QUOTE]
I just bought my new 21 inch imac,and was in two minds whether to spend £1700 on a 27 inch with fusion and get more RAM later on,or spend around £1500 on a 21 inch w fusion and more RAM.
In the end when i was in the Liverpool apple store last week i went and bought a standard 21 inch and love it.
The 21 looks tiny next to the 27 but when i took it home i was really glad i did'nt get the 27,it would have looked massive.
Last night i was rendering a 1gb movie with itunes playing and browsing safari and had no problems,unlike my last pc when rendering i could'nt even browse the web.
Plus i am a mac newbie and did'nt want to spend all that cash without knowing if i could get round to everything imac.
Saying that though in three years time after my apple care runs out i might consider selling this one and looking what the latest mac then has to offer.
Glad i took the plunge and got one though.
Ian