So I had been itching to try these out for a while, and while at Vai Academy I got to play/use/abuse them because Steve has them on his guitars (the abuse http://instagram.com/p/qKd1bryBEY/
In short- I love it. It's fantastic
The first thing- it's extremely light. And I know that's in the title, but seriously it's lighter than you'd imagine. Which means- almost no mass for flutter. Causing all te flutter to come from the bridge, making it short flutter and not very thick, like when you have a backstop in. (But it's still enough to keep me satisfied)
Two- it feels awesome. Te bar itself is soft, it's almost like that 2500 grit sandpaper softness (except it's not rough at all). It's also thicker, which makes it more comfortable to handle.
The bar makes the whole thing feel more stable and more comfortable.
I use the whammy bar a lot- it's necessary for when I play because it's become part of the way I play. An ordinary person who uses the bar once in a while does NOT NEED IT. But for people who use it a lot, this bar is a must. There's no going back really.
Also- it's kind of scary. When you look at it and move it around, the material gets all kaliedeacope-ish. So you can scare anyone who's watching you
I ended up buying one as soon as I got back- $90 is a lot, but if you're careful not to break it then it's worth it.