Ironically, I was subject to advertisements for it when I was searching for a job this summer and did mall polls.
While I did not get the vibrating model (ed note: it's potentially worth it with the nice rounded tip of the handle), I did get the metal razor with replacement heads. It's been years since I had a 'real' razor, opting for disposables and electrics. The first thing I noticed was how awkward and poorly gripped the razor was when lathered and wet in the shower.
It's gotten significantly easier to manage after shaving my whole body 1.5 times with it.
The fusion has 5 blades on it. And it may just be that I'm getting more skilled at following the natural growth of my hair and not applying undue pressure, but the blades seem to be MUCH MUCH less likely to lacerate my skin than the shick 4 blade disposables I'd been using were. Every time I thought I'd ripped myself apart (which was not that often, mostly confined to the front of the shins and back/top of the knees, naturally difficult areas), nearly every time I found myself not even bleeding. Typically with my old disposables, I'd find myself bleeding even when I didn't feel that I'd been cut. It also gives an incredibly close shave.
The last neat feature on it is that on the front of the razor is a sixth blade by itself, designed to be used like a straightedge in difficult areas, particularly the face. It works fantastically for that purpose, with due care it handled my laser-thinned (but still quite bushy, stupid blond hairs) goatee area quite well. I didn't get the chance to shave my entire face because I was in the shower and had no mirror, and didn't want to risk it with a new razor even with how promising it seemed, but it felt like the easiest shave I've ever had for my face.
The Fusion has given me the confidence to shave the backs of my thighs, and go against the grain on the front of my thighs, two places that I absolutely refused before. I have an incredibly awful reaction to hair growth and am prone to terrible rashes or ingrown hairs, but the Fusion seems to be preventing that for now. I may, in time, even go against the grain on my face with it, but that's a huge risk for me.
It cost me about $8 for the handle and two heads at wal-mart. The happy vibrating model was another $2, I didn't get it because I hadn't been particularly impressed by the vibrating mach 3 I had 4 years ago, but your mileage may vary considerably. Just be careful of the imprinted text near the end of the handle.