I am 1 for 6 on the Genius Bar at WC, and just seem to have a significantly better ratio with Galleria (as in so many more good that I don't even keep track anymore.) I haven't gone back to the WC store since they reopened in the new spot. I cannot figure out if the Galleria just gets the better tech staff due to proximity to downtown/clayton/schools? I mean, that has to be it.
Neither is really geographically better for me though, I work downtown and technically the mileage is about equal from my house (SoCo) so I just base it on what I "need" from whichever Nordstrom/Sephora and or whatever is near that mall (Ulta/WholePaycheck/whathaveyou). I prefer the Galleria Nordstrom/Sephora though, so I think I tend to just go there more. The Galleria is "easier" to get to from downtown, in theory, but I do get off early enough that 40 isn't so bad that I want to kill myself.