After trying to work out the relative merits of Fusion v SSD I've decided to go with the SSD option. Now trying to work out whether to go with the 512Gb or 1Tb version. The price difference between the two is £375 for BTO. I currently already use around 700Gb on my iMac (and have already moved my movies on to an external drive) - however, I could easily also move my music, photos, iMove projects and documents to an external drive too to get my usage requirements down to around 200-300Gb. However, other than just going for a straight external USB HDD what are my best options for external storage. Is this effectively only going to cost me around the same amount as upgrading the internal SSD in the first place? Thanks John.