really think Adobe should not release a new version of a product as important as After Effects until all the bugs are resolved.
The first release of any software will have some bugs. With the (literally) infinite number of possible hardware and software configurations out there, it is impossible for them to test every eventuality.
Granted, this release is a bit buggier than AE usually is. However, considering how much has changed under the hood, I'm surprised there aren't a lot more problems! This is the biggest rewrite of AE's code since, well, I don't know when, but it's huge! It's a bigger deal than when they went to 64-bit in CS5, I know that!
I am not having the troubles you are experiencing. Neither are the majority of users. Thus your issue isn't a super-common one. Please file a bug report so it can be fixed in the next update. Give them as much detail as possible; they can't fix what they can't diagnose.
If you don't want to be on the cutting edge, wait a month or so for the bug fix update that's targeted for July and continue work in CC 2014 as if CC 2015 isn't out yet. And, if you accidentally left the Creative Cloud software's options set to remove CC 2014, remember, you can still download and install every version back to CS6.
OK I see that there are significant changes. I do find that the Preview/layer_controls/off_or_use_current_setting does not seem to work. The Space Bar preview always takes its resolution from the comp setting.