To all who are complaining about EXP glitches: it is partially intentional and partially not.
The live beta recently had the BW experience system added to it. Oddly, I found none of these problems when testing it myself.
If one Pokemon receives less EXP than another in a split battle, that is because that Pokemon is a higher level. That is intentional, however, the no experience may be caused by a flag glitch - I shall need to investigate that.
I also did not find the slots glitch for exp gain that you are reporting. I suspect it is caused by the same glitch.
As to the super exp gain - I have no idea what's causing that, so could you give me some details to follow up on to see if I can fix it.
Also - we did say the live beta would potentially be very buggy!