I have a couple of these adapters. They have pros and cons. My experiences with them is that, once you've stopped your FD lens down to f/4 or slower, they work ok and image degradation is very small. But trying to shoot at faster apertures just doesn't work. There's an increasing amount of flare as you go faster and faster, until, but f/1.4, the image is totally unusable. So you won't be able to use any of your FD glass that's f/2.8 or faster.
Here's my recommendation: if you have a sizable collection of FD glass and you want to use it on a quality digital camera, then you should seriously consider the E-mount Sony mirrorless cameras. I have a NEX-7. I bought an FD adapter, with tripod mount, for $15 on eBay. I now have infinity focus with all my FD lenses on a great digital camera. As a former EOS DSLR user and still a current FD film user, all I can say is, at last I can enjoy my FD lenses in the digital realm. And I'm loving it.
But since this is an analog forum, I recommend you pick up a nice FD camera, like an FTb or an old F-1, and just shoot with the manual-focus FDs. If you want to use EOS cameras, then buy EF lenses for them.