While pinch flatting can be alleviated to some extent by carefully monitoring air pressure (and of course avoiding potholes, etc., when possible), some tubes pinchflat easier than others -- Vredsteins, for example, due, I think, to them being thicker and less compliant. I bought three Vredstein tubes a couple of years ago, and they ALL pinch flatted to death, they are the only tubes I've ever pinch flatted with on my road bike (always at 120psi before i ride). Add to that fact that the Vred tubes were both heavy and expensive, and I stay clear. Conti tubes seem near identical to Specialized tubes as near as I can tell, and I have had valve problems with both, probably due to the fact that I use a Slica pump, and their threaded stems can take a little "thumb-grease" action to get the Silca head on and off.