I have an L2T 2.0, which sounds very similar to the one mentioned in the first post. It is like riding with a car headlight on the bike. It scares pedestrians. In order to get a bike light that bright (about 120-140 lumens), I would have to spend a lot of money. Plus, the Fenix is useful off the bike, and it can easily be removed so that it can't be stolen when the bike is parked.

I highly recommend them, even better if you have two!

EDIT: I forgot a few things...

I use rechargeable batteries, which saves money. NiMH is the way to go, unless you want to shell out for rechargeable lithium.

Also, I should add that a bar mount is better than a helmet mount. Human eyes aren't really good at seeing shadows when the light source is coming from very close to the eyes, like on the head. You could totally miss a pothole even though it is illuminated. The best solution would be one light on the bars and another on the helmet, so that you could look into turns and so on.

I use the bike mounts sold on Fenix-store.com, which can easily be used on helmets, and are also useful for mounting U-locks and pumps that don't have brackets.

Also, some of the nicer Fenix lights have a strobe mode which some people might like.