No Chrome!
Needs to be 300g +, standard one does already have a bit of weight in it ( I can't remember how much, a while since I weighed it ), so it has to be heavier but not too much so.
I can't remember who but someone here was using the Razo RA25A which is 340g and noted a positive improvement in shifts.
But then again over $100 just for a gear knob has made me reluctant to go down this path, better things to spend it on ;)
awe, come on, just try it out! the damned thing is about 500 gms... u'll shift so smooth, u'll love chrome! and u get to play with it for free!