Upgrade to 10.6.3? I don't think so.

[Nermal]

The majority of the users who have no issues, you won't hear about them.

Exactly. I've upgraded both of my machines, no noticeable changes on one, and better gaming performance on the other. It also fixed a system sleep issue that I've had since installing my (non-Apple) Radeon 4870. So I'm happy

 

[Stonefly]

There's a pretty huge list of security fixes in 10.6.3. For that reason alone, it's worth upgrading to.

It's why I didn't wait and took it last night. Haven't had any problems.

 

[amoergosum]

GREAT update with no problems here!
Photoshop performs faster...sweet!