Quartz is currently working fine for me without having to turn off any features. The only problems I'm having are with configuration. I'm assuming this is because 3.0 changes the way AddOn settings are stored, apparently "some" settings are/can now reside server side.
For those that are interested, there's an informative post on the US WotLK Beta forum (UI + Macro section) that lists all working mods. Link:
WoW Forums -> Functional Add-ons
Tip: If you find that an AddOn is working (as in it displays or functions) but you can't configure it to your needs try this:
- Load the AddOn in the live release of WoW
- Configure it to your needs
- Close/logout of wow to commit the changes
- Find the SavedVariable file associated with the addon and open in WordPad
- Do a find and replace with "Your Realm Name" to change to "You Beta Realm Name"
- Do a find and replace with "Your Live Character Name" to "Your Beta Character Name"
- Copy the Lua file into the WotLK equivalent folder (replace if neccessary)
This is what I did with PitBull and Quartz as the Ace2 config window kept throwing errors.