Well I run Windows 7 Ultimate X64 and it tends to eat up a lot of space (the sysWOW64 folder can grow quite large over time). This is a new build and I only have two games installed right now to my OS drive, and I'm already eating up 420GB! And ALL of my media, except for a few pictures are stored on separate drives. Of course, one of those games is GTA V and it eats up around 65GB on it's own, lol.
But I'm still happy to test this SSD. I'll probably use it as a slave drive and install the games I'm currently playing onto it. I haven't been gaming much at all over the last year and a half, but I just bought GTA V so I'm playing it more and more now. Plus I also have Witcher 3 when I got it free with my GTX 970, so that will be another game I'll likely start playing soon.
P.S. Just as an example, my "program files(x86)" folder is eating up 114GB right now on it's own and I swear I don't have a lot of programs installed as this is a new build. My current Windows folder is eating up another 22GB and that will only grow as the sysWOW64 folder grows. It takes a heck of a lot of maintenance to keep your installation streamlined, which is something I don't want to bother with too much beyond using CCleaner every so often.