I use mostly all GP gear. Its always been consistent for me, since I started using them in 2009 or 2008. I've used their test e, cyp, sust 270 and prop. Each one, I've used a number of times. I've been on a kick with the Sust 270 for the past couple of cycles. Also, keep in mind that it's all a little over dosed. You can see that by looking at their lab results or getting blood work done, if you keep track of your test levels. So don't over do it. It's strong gear. You also can't go wrong with human grade. It's more expensive, but you never can go wrong with human grade.
I don't think there are any "bad" brands on Naps though. I've worked with guys using a lot of the brands available and haven't found any of them to be a problem.