I've currently got a 2008 Mac-mini (2.0Ghz with 2GB RAM and 160GB SSD) in my office and it's grinding to a halt, or at least compared to the 2011 MBA I use when I'm out and about. Money ready and waiting to spend on a new iMac, but still undecided on specs. I think I'm swinging toward the 21" with upgraded processor and SDD/HDD and will upgrade the RAM myself but the 27" keeps on tempting me. I currently have a Dell 22" monitor connected to the Mac-mini, so don't think I'd miss the extra desktop space I don't currently have. Budget is limited to £1800 so do I got for bigger screen and slightly lower spec insides, or maximum spec insides and 21" screen? Decisions decisions What would you do?