TWM has a new knob out that supposedly addresses some of those concerns. Here is a link to it, the phantom knob. I think it's a pretty sweet name haha.
I really wish I could try a weighted shift knob locally to see if it is really worth it. 150 dollars is a lot of money for a knob!
The weighted knobs do feel really nice, especially with a short shifter...helps put it in to gear a little easier. I actually made myself shift knobs out of lathed/finished/tapped maple for the winter time - the do not get anywhere near as cold as the metal ones. They are not weighted, but warm up very fast, which is nice in winter! Or march...when it's still snowing...(notcool)