People equate driver tweaking UI == driver
I always hear horror stories about people having to go through a long and pain-in-the-neck process just to get the drivers installed correctly, not to mention bugs such as the cursor corruption and having idle clocks so low the computer crashes. Not to mention the few times I've used computers with ATI cards there were huge problems with even simple things like video playback.
If none of this has happened to you then hey, congrats. Maybe those were just isolated incidents. I do think they put more effort into their cards than their software though.
2 days ago i got a Sapphire HD5770, 1GB. Downloaded latest Catalyst and Stream 2.1, installed both, reboot: that's all.
Everything is working: h264 acceleration, mining, gaming, multimonitor (the card is coupled with an nVidia 9400gt) without any issue at all.
Windows 7 x64 here.
What's your average hashrate? I've got the same setup, but with Stream 2.2, and I'm getting ~315 mhash/s (as opposed to ~300mhash/s with Stream 2.3)
EDIT: Mirror for Stream SDK 2.2 for Windows 7 x64: http://www.megaupload.com/?d=E7FU5U2E