Not meant sarcastically as the Mac client actually runs smoother for me than its Windows/Bootcamp counter-part. Better FPS, richer colors, and rubber-banding while riding a warhorse is pretty much gone since I have managed to jump every river I've come across perfectly instead of being dismounted and my character suddenly appearing 10ft from where I see him - which happens on the windows client all the time. That and riding across town at 4.2MPH then being sling-shot back 400ft because actually I'm stuck behind a wall. None of that on the Mac client.
However the little thing doesn't work. The thing you use 100% of the time. The thing more important than FPS, colors and rubber-banding. Keybinds. You press them every second you're in combat, when you mount, dismount, buff. I have many reaction abilities tied to scrolling the mouse wheel up/down with shift/control also. This doesn't work on the Mac client, nor does the middle mouse button(s) or the two on the side of my particular mouse.
I will be keeping a close eye on these forums for the coming updates to the BETA client, and hope to see an actual finished one soon because honest to God except for this one crippling (for my playstyle) aspect, this client blows the windows one out of the water.
See you soon. TM.