I'm thinking about getting an iMac. I might wait untill the end of the month to see if there are any news on the 2011 update. Either way, going from a SSD to HDD would be a massive downgrade & I don't need a 256GB SSD for £450 when I can get a 120GB for £170 (which is more then enough). Is there space for a SSD & a HDD in the 21.5" iMac or would I have to get the 27"? Does the iMac come with the OSX CD/DVD so that I can install it on the ssd & use the hdd provided for storage? Will opening the iMac void my warranty?