Shadow, you don't say what you intend to use your dynamo for - that info would help the replies, I'm sure.

I use a Son 28 front hub dynamo on my touring wheel, coupled to a front light and a cycle2charge unit to charge electronics. I don't use it for a rear light, simply because the cabling would be too messy, althought he power output would be more than enough.

I prefer not to charge my electronics directly from the hub, instead using a battery pack to charge from the dynamo, then charge the electronics from that.

Until recently, the hub was a luxury in that I didn't really need it because there was always the opportunity to charge my pack at a wall. But for the last few months I've been testing the "system" using only the dynamo and it works fine. I can generate enough power to charge my new toy (GPS), my phone and my kindle.

Hope this helps

Frank