Try disabling pixel shaders in winecfg to get around that. They never did work for me. I tried to use them yesterday with HL2 to get some screenshots, and they froze my computer. If you're lucky enough to even star a game using them, they mess things up anyway.
Alternatively, you could try filing bug reports for the problems you experience, rather than working around them. If no bug reports are filed, nothing will get fixed. Anyway, I see that the patch from Oliver which implements pixel shaders hasn't been merged yet, which might explain why they aren't working...
Visually, I would say it looks better than I recall getting from Cedega. The textures on the monoliths were always plain and flat when I was running Cedega. I'm tempted to renew my Cedega subscription to make sure I'm remembering right.
Yeah, I know what you mean. I've never been a fan of Cedega, so I say to hell with it. I would stick with free WINE. ;-)
...and yet you have no problem making use of the Transgaming ActiveX control, which contains Microsoft DLL(s) within?