I find the CE 2 XL's perfect right out of the box and me and a couple of friends agree as we have bought 200 of them from China. We find that the R4's are better than the R5's by the way.
Maybe just the luck of the draw as the R3's were atrocious things even in homemade syringe tanks.
RC
Well I never had any luck with them so I quit trying and buying them. Same as another vendor that GOT my money enough times for products I don't like. I won't buy from them either.