I can't decide between the 256GB and 512GB SSD for the 27" iMac. I plan to put the following things (of significance) on the SSD: - Bootcamp with OS X and Windows 10 (incl. drivers, updates etc.) - Chrome browser (incl. cache etc.) - Steam with one big game (e.g. Skyrim) and a few small ones (e.g. Rayman Origins) installed - Microsoft Office - A few smaller apps: Tweetbot, Plex Media Player, GoodSync All my data, except a few documents that I fequently have to access, will be on an external hard drive. Could anyone give a rough estimate of how much space all this would require?