[davesST]

I have a WC Lathewerks stainless steel knob on mine and like it quite a bit. It weighs in at 440g. I wish I had seen this website you're looking at. I could have got the same design for even cheaper, and it weighs even more than the one I bought. My ST has kind of a notchy feel on the 2 to 3 and 4 to 5 up shifts even after the FSWerks aluminum bushing upgrade. I find the extra weight helps out a bit.

 

[davesST]

I suppose it is possible. However, 550g is not going to hurt anything, unless you are attempting to do a bunch of power shifting. In that case, you may cause premature wear to the synchros. Just make sure you are not resting your hand on the shifter and you'll be just fine with the 550g knob.