I am replacing the hub on Heather’s bike with the new velo orange dynamo hub. It is well built and features a clutch to engage the dynamo portion. (See note below) The difference is night and day when just turning the axle. The difference is more subtle when turning the wheel on the truing stand. Since she is a more casual rider, I think this hub will offer the best solution since it is my understanding the dynamo hubs use comparitively more energy from the rider at slower speeds.
This is my third wheel to build from scratch. It went together in about one hour which is much faster than the last two I started with.
UPDATE: Velo Orange has listed this hub as “Out of Stock”. There have been numerous issues with this hub and I think they have pulled out selling this for now. I found the clutch disengages from the generator when you start pedalling moderately hard. This causes the light to flicker on and off. I had this happen to 2 out of 3 hubs I owned. This one product DOES NOT represent their whole quality product line and their customer service was outstanding in dealing with the issue. Good for them to pull the product than sell more defective units. Just be aware if you see any used units popping out, there is a reason why they are being sold.
I am now using Shimano 3n80 dynohub. They work very well and are reliable. They have practically insignificant amounts of drag.