What kind of mods are you using ? Have you tried very high ?
Mods-wise I pretty much only use MC Command Center (plus things like no zzs, no music notes etc.).
"High" is the highest setting for Reflections. My settings are custom, with everything on highest except for Lighting (had it on Very High, but lowered it to High after C&D – whatever the patch changed, my computer didn't like it) and Effects (not sure what that setting does, I've lowered it to Medium). I've also recently turned off AA, as I don't see much difference, having a Retina display.
Basically since C&D I'm hitting some kind of CPU bottleneck (very high CPU usage, very low GPU usage). Not sure if the reflections issue is related, as I haven't visited any lots with pools for a long while (until yesterday).
Might be a mac issue so tagging @Bluebellflora
I assume you have taken out all mods to test as well (just to be sure) ?
