Not bad, sir. Not enough cussing though. LOL! Just kidding! Seriously though, good job.
You don't have to use a mic. I mean, if you can afford one, great. However, I'll just record my narration seperately. I sit the camera a foot away from me and run through my review three or four times, than I'll use the pieces that sound best from each take.
Another thing you may want is a light. I bought one of those clip-lights from a DIY hardware store, along with a pack of 60watt energy saver bulbs (I like the blue hue it casts). Shooting dark objects tends to suck the light right outta' the picture. Like, it takes three lights for me to even see my Genesis on tape. It doesn't help that it's on a dark shelf. Hehe. But, yeah, that's really all I'd suggest. Otherwise, keep at it, sir.