I've had poor luck with Performance brand tubes and tires, I sure as hell am not going to try out whatever brand Walmart carries. I doubt they carry any 700x23 anyway. Besides, what does a tube cost? $5? I've used a few during the past year. I've gone through probably 2 tires during that time but I know for a fact that Walmart isn't stocking Continental GP4000 tires.

BTW-Giro Atmos helmets don't fit me well but the Bell Sweep, which is what I'm currently wearing, fits me perfectly. On a side note, I tried on one of the latest Giro Atmos helmets and it actually felt more comfortable than some of the ones I tried on last year.