Hahah well Vegas is actually one of my favourite places in the US (next to NY which I try to visit almost every year) but my priorities are different because I love Broadway, theatre and all sorts of shows and concerts, which Vegas has PLENTY of.
We both haven't been to SD but I find the service in Vegas impeccable. They remember you even when you're a tourist who only comes by 1-2 times a year and I think my best friend already had her shopping list set aside for her at specific boutiques. Which explains why she suddenly called me today to help her get a badge refund because "Sorry babe but I just booked a flight out to Vegas!! ENJOY THURSDAY ON YOUR OWN!!" ...have a feeling she may take a couple days more to be honest. :P On the upside this frees up more badges for ardent SDCC fans.