I've just got it.
It seems pretty faster, and the addons thing looks good. I've got something called CoolIris which is a bit 'nifty'.
Major advantage: I can now copy and paste from DiS, without copying the whole page.
Major disadvantage: I'm bombarded with irritating windows like 'Welcome To Firefox! Want to customize your bla bla?'.
Are there any amazing tricks it does that I can look at and go 'WOAH!'?