Be aware that this was just a single negative experience but, since you asked:
I once ordered a Riva kit from a prominent online vendor and they shipped me a kGo instead. The batts looked like Riva batts (same black w/gold trim appearance) but the build quality was obviously inferior (the metal used for the gold banding on the kGo looked like crappy pot metal). Neither of the two kGo batts would thread an atomizer on straight and one, initially, wouldn't even thread an atomizer all the way on at all. I was able to correct that one after playing around with it for a little bit. They had failed to deburr the threading during manufacture. Needless to say, I sent it back and got a refund.
So yeah, based on that one experience, I cannot at all recommend a kGo.