The SON dynohub and Supernova products are great. As a matter of fact they are probably the best that money can buy. They will last you a long time and give you flawless service, but the question is this:

Are they worth the money?

I commute 10 miles each way to work, and during the winter months it's dark when I travel both morning and evening. So dependable light is important. I also ride long distance rides that often take me into the night, so that dependable light must also be efficient.

Last year I decided that the improvements in LED technology warranted making the purchases required to try out a dynamo hub and LED head unit. I nearly bought the SON hub, but after researching opinions and comparisons... I decided to go with the Shimano DH-3N80 hub. I found that most people agree that this top shelf Shimano hub is nearly on par with the SON... it's apparently so close in efficiency that you can't really tell a difference. Mine has been great. No regrets. But the SON definitely is a nicer hub, so if you want the bling factor then buy the SON. But the Shimano is half of the price of the SON.

As far as LED head units go... I bought the IQ Cyo unit. The Supernova is nice with its machined housing and all, but it is expensive. My IQ Cyo has a plastic housing that doesn't spark much excitement, but it puts out a shocking amount of light. I ride on both well lit city streets near work out into the pitch black countryside near my house, and I really don't see how you could need much more light than this unit puts out. And it cost me $105 from Peter White Cycles.

If you really want good light without worrying at all about batteries, then you really need to give dynamo lighting a go. But just know that high quality stuff can be had for MUCH cheaper than the SON/Supernova price point.