I don;t miss leakage or weak hits at all !!!
I've never noticed a metallic taste either. I love my pro-tanks. The Model 2 is coming out, and you can get a plastic tip for that, but it is designed in such a way that it might be more prone to leaks than the original. (top o-ring connection). But you can change tips.
What tip cover ? none in pkg... fancy box set too...
Mine came in the discount package, and had a silicone cap on the top of them. I figured it was for shipping, or to keep the tip clean when it's in your pocket. I use them to stand the tanks on the desk if I have to fiddle with the coil.