I have been to Verizon amp in Alpharetta, it's 20 mins from my house. Cool venue, about 12k people. The parking is broken into a few lots, if you get lot A that is closest to the venue. Always a good scene there. As with most venues if you are stealthy you will have no problems. Inside the venue you have to be even more stealthy. great venue though.
I have not been to Simpsonville, although I will this summer! I hate to wish time away, but summer can't get here soon enough!