I'm a newb commuter, and have only used this product for the past 2 months, but I did a bunch of research and decided on the frictionless magnetic induction method of generating electricity using the Reelight RL770. Got the full kit for around $78 US. I can only think of the PROS, and can't think of a single CON, except maybe the added weight of 1.5 lbs. max, which is well worth the peace of mind.

http://reelights.com/shop/index.php?...roller=product

The most important part to me was that the lights are always on (as long as the wheel is spinning) which means you will never forget the batteries nor forget to USB recharge, and you won't spend time keeping track of that battery/recharge equipment. There's a built in capacitor that allows the tail light to stay on for 4 minutes after the bike comes to a stop, which is important at an intersection or stop sign. The whole thing mounted very easily, and the gap between the magnets on the spokes and the receiver is nice and wide and forgiving, maybe a 1/2 inch.

BTW: This Commuting forum and archives have helped me a bunch, as well as keep me motivated. Many thanks to all who have come before me.