I use One Step and love it. I also purchased a three-part polish kit from Novus and I like it about as well. Both products work the same way: tiny little bits of abrasive suspended in a slurry of polish.
Novus has three bottles of stuff, one is a heavy scratch remover, one is a fine scratch remover, and one is a plastic polish. Of these, I think only the fine scratch remover is a benefit for pen making. The heavy scratch remover works fine, but is not as fast or as even as Micro Mesh. The plastic polish is really a plastic cleaner--good for removing fingerprints, etc, but not much else. If I ever do a show, I'll bring it along to keep the pens looking good.
One Step is virtually indistinguishable from Novus 2 in performance in my eyes. It does exactly the same thing, and seems to work exactly the same way. One Step is a bright yellow/white color where Novus 2 is brown, and that's the only difference I can find. Both are really good products, and easy to use.
Novus does have One Step beat on price. You can get an 8 oz bottle from Amazon for under $8. One Step is $12 for 3.4 oz, and you have to pay PSI's shipping.
I guess that's more info than you needed, but definitely try one or the other. The results are so easy and effective, it'll feel like cheating at first. Also, try either product to restore your headlights! Just rub a little on with a paper towel. My buddy turned me on to this, and it works great.