You can spot the fanboys like The Dude because they claim their "perfect" experience is the same one that everyone buying the product gets, but anyone with a different experience is either a liar or someone you shouldnt be paying attention to. So yea, fanboy.
If you don't have a perfect experience, it would seem like there are a few options:
1) Something is wrong with the hardware (e.g., battery, screen, whatever)
2) There is incompatibility with some newer software (e.g., Google Chrome)
3) The reality doesn't meet your expectations (e.g. minor scroll lag in Facebook).
#2 and #3 are part of being an early adopter and the majority of that should be fixed with ML and as software vendors catch up.
So the options are either return the system (if it is #2 or #3) and wait a few months, years, etc or exchange the system (#1).
I actually didn't notice the Facebook lag until I read about it. Facebook on this system is much faster than my last system though so that could be the primary reason. The safari lag in general is barely noticeable to me.
I didn't install Google Chrome after I read about other users issues. And I'm willing to wait for the software to catch up. I even used Pages and I didn't have a problem with it.
Again, if you aren't happy with the system after you buy it, then there is no harm in returning it.