The 27-inch iMac we tested costs £1,699, and that's not nothing. You do get a very stylish computer in aluminium with above-average specifications. It has an excellent 27-inch display, a powerful processor, 8 GB of RAM and a fast graphics card. The main drawback is the slow hard disk, in a configuration like this an SSD should be standard.
Any major computer upgrade generally requires a full software reinstall too. No so if you heed the advice in the guide to Upgrading a Motherboard without Reinstalling. PCSTATS Tips