I've had fairly good luck with it (if you browse the civ forums at codeweavers, I've posted about it there a bit). I haven't gotten updated to 3.19 as I stopped playing in Crossover as I was having OOS errors when hosting Fall From Heaven (I do most of my playing in MP). Very inconsistent but happened more when running in Crossover than on the bootcamp PC.
It's definitely a ton faster than running in a VM, but not faster than native (either boot camp or how I'd expect the Mac side to be...).
With regard to the CRC install errors - I've definitely seen that, my disc does that under windows when I've had to reinstall. Sucks. I usually just polish the disc a bit and keep trying while crossing fingers and toes...
When I install in BootCamp and drag the entire install to my Bottle, however. If I were to update to 3.19, I'd just drag my current 3.19 install over from that partition (this is far easier, but understandably problematic for those who don't have bootcamp or a VM partition..).
One issue that *I* have (oddly) is that it will *only* run in full screen - I can't tab out (alt or Apple), which is problematic at times. I don't think I've tried changing the setting that runs it in a window, however.
I don't think I've seen that last problem, Flintlock

On thing I had to toy around with was the settings for where My Documents were, but I think that was for finding saves and mods, so I'm not sure that's relevant.