I just got a 48 tooth STM billet basket, plates, and billet pressure plate. They are beautifully made parts, and I like them a lot.
However, one thing I found is that while the STM basket and pales were lighter than stock, the pressure plate was heavier!
The stock pressure plate weighs 9 oz.
The STM billet one weighs 11 oz.
I've seen the CycleCat one on their website. It is beautiful, but I have no idea what IT weighs.
Of course it's also valid to say that if there is one place you want stiffness, it is in your clutch pressure plate! Normally, a little more weight results in a lot more stiffness, all other factors being equal.
I have not had the STM clutch long yet, but I noticed RIGHT away that when selecting neutral, it SNAPS right in much more authoritatively than with the stock clutch.
Free: I didn't actually do any shopping at all. My dealer happened to have had the kit in stock "a long time" and offered a good deal when I epxressed an interest.
All other things being reasonably equal, I like to try to give my local dealer first shot at selling me parts and accessoires, as I appreciate having LOCAL support and help when I need it, and of course the dealer has to be able to make a living in order to BE there!
Don't underestimate the value of a local dealer relationship, when you have a parts problem, a warranty issue, or just want a favor.
My dealer knows I am fascinated with the 749, so when he recently arranged for a day of demo rides, he made sure I got a 1 hour ride on one.
When the first attempt at installing the STM clutch went badly, the mechanic called the supplier, talked through the problem, and got a replacement part shipped out OVERNIGHT (STM had made some that were not quite right, and I guess we had one of them). He also refused to charge me for the doubled installation labor as it was "not my fault".