I have a SRAM i-Light D7 disc driving a Supernova E3 symmetrical. Cars flash their high beams at me. I love this light and hub. I have read some reviews of the i-Light hubs wherein the bearings needed replacing after a year. My hub has been in use for 18 months now, with about 12,000 miles of Portland OR commuting and randonneuring.
Everyone with whom I ride uses either a Shimano (the majority) or Schmidt (distant second place), and most of them run Supernova lights. They are all extremely happy, too. Seeing their lights in use is what convinced me to make the jump to dyno. I went SRAM because I don't like Centerlock (thanks for the proprietary tools, Shimano) and didn't want to drop the $250 on a Schmidt without having sussed out the dyno light thing. I can totally stomach the entry fee for Schmidt now, but I am happy enough with SRAM to stick with them. There are other hubs, you can get into a Sanyo hub for $40. That hub has cartridge bearings. It is difficult to buy a plain
cartridge bearing front hub for $40. I also have a Velo-Orange switchable dyno. This is a gorgeous hub that takes a good amount of abuse that I have ditched out. Unfortunately, Velo-Orange seems to run out of these pretty quickly. It's slick because you can actually disengage the generator, thereby reducing the small, yet measurable, drag from the dyno.
I think that dyno selection is less important than light selection. It is amazing what lens/reflector design plus a couple generations of LED evolution will do for lighting. One of my employees has a B+M IQ Cyo and it is a decent light for the price. If you're looking for outright paint-peeling illumination, Supernova E3 Triple is pretty unbeatable. In general, you're probably looking at $100 to $250 for a light worth owning. Uncle Pedro has some really good beam shots and comparisons
. This guy
also has a lot of really great info and reviews. He also has the benefit of integration spheres for objective measurements.
One of my great issues with dyno lights is that none of the models I have seen have a high/low setting. This is probably a non-issue for most people, but when putting in long hours at night, I would like to save the eyestrain.