You should know the answer to this, Captain. First, those issues only ever affected a minority of PB owners. Second, every computer made by every company has the potential to have a few with "headaches." Apple is no exception, but it could even be argued they are better than most. Thankfully, all new laptops you can buy come with warranties too.
That said, the general consensus on these boards (a skewed sample) seems to be that this is of course a pretty trouble-free 12" rev. D. That doesn't mean some people won't have some problems with some of them, but I wouldn't expect anything less of any laptop in existence. The one caveat on this might be the new trackpad, but again, we here are more likely to hear about the problematic ones than the ones working just fine.
In short, I would not be stressing over this. You should be fine.