When I first started looking into generator hubs in early 2013, I found a nice set of articles by a cyclist in the Netherlands who reviewed a number of different pieces of equipment, including hubs and lights. One issue that he found annoying, but not a show stopper, was vibrations felt in the handlebar from the generator. He gives some reasons for why this may occur but concluded that there were too many variables to narrow done a cause or to lower the vibration effectively.
After doing some reading, I had Harris Cyclery build a wheel for my Surly Cross Check. They used a Shimano 3N80 hub laced to a Mavic Open Pro rim to match the Surly build. And guess what ... I have a decent amount of vibration coming from the hub. It isn't evident below 18 MPH and it doesn't get stronger the faster you go. Not that I am exceeding 20 MPH often at night but I do have it turned on during the day for safety. It's not to the point of annoying but it is obvious that I am feeling vibration in the handlebars. If I were on a road ride, riding above 20 MPH for a decent amount of time on the ride, I might think it would be annoying.
My reasoning for building a generator hub for this bike was that I would have lights for commuting and would have the wider tires for the bumps that I wouldn't see quite as well in the generator light. It all worked out well. I used the daytime running lights on all of my commutes and feel that it works well for me. I also have done a substantial number of early morning and late night rides, some on dirt roads, and have loved getting out at night. It's magical and as long as you take great care, especially if you are riding alone (it's more magical and you need to be much more careful on your own). One issue for me was that I was trying to do longish rides (for me, maybe short for you) and starting at 5 AM in late August or September meant that I needed lights. And that meant I was on my Surly, which isn't built for speed or distance (not that I haven't rode 60 road miles on it once or twice). I found myself wanting to go farther and faster once the sun rose and I was slowed down by the bike. So I thought I should add lights to my IF so that I had my fast bike for those early starts.
I started out with getting a last generation Busch and Muller IQ CYO headlight (that matches the Surly and is sufficiently functional for me) and a Busch and Muller Secula Plus taillight for the IF. I had these mounted before my first ride in the spring (and probably looked dorky to every who noticed my generator lights sans generator hub - only one person said anything to me). I tested the wiring using my Shimano hub and all was well. And when I had enough money (or permission to spend the money), I order a wheel from Ride Studio Cafe. I think that Harris Cyclery did a great job building my first generator wheel but I didn't love getting there. West Newton is a pole of relative inaccessibility for me and I ended up going there a few times getting the new lights and the Sheldon Problem Solvers (for mounting the front fender after you had the headlight set up - ask me if you want to know more), and something I can't remember anymore. In any case it seemed like a major trip and Ride Studio is a great shop and much easier to get to.
Ride Studio built up a great wheel with a Shimano Son Deluxe hub laced to a Mavic Open Pro rim (there is a pattern here). I picked it up in late July mounted it last week and, guess what - no vibrations:
I test rode my new SON Deluxe/Mavic Open Pro wheel built by @ridestudiocafe this evening. It's beautiful! No vibrations at 20+ MPH.
— NE Bicyclist (@NEBicyclist) July 31, 2014
Based on my Garmin feedback, I hit 25 MPH and there was still no vibration. I don't think I ride over that speed all that much, except on downhills, so I think I am pretty sure that this combination (IF, straight blade steel fork) is a good match for the wheel that Ride Studio built for me. I was out this past weekend on an early morning, misty ride and it was great to have solid lighting. I did have my Nite Rider battery powered light but I didn't feel like I needed it and didn't turn it on. I also had a Portland Design Works Radbot to supplement the Secula Plus, and I did have it on when on the road.
In short - get generator lighting if you can afford it and hopefully your frame doesn't transmit a lot of vibration to your handlebars. I experience it on my Surly, but not on my IF. And at the speeds that I feel it on my Surly, I don't feel it that often. And it is nice to not worry about charging batteries. And maybe I'll buy a charger so I can charge up my phone and Garmin on long rides when I don't need my lights. (That's one drawback of the lighter Deluxe vs the Son 28.)
If I really wanted to test the vibrations on the Surly vs the IF, I would have switched the wheels (and the tires) and the connections (the Shimano generator hubs uses a very different connector from the raw connectors that the Schmidt hub uses). I would be able to tell you that the Surly does, or does not, have vibration with the Schmidt hub and that the IF does, or does not, have vibration with the Shimano that the Surly has. But as my buddy Carl suggested, like the Netherlands writer did, there are so many variables that you really can't control for everything. So this was not a test, just a recounting of my experience with these two hubs on different bikes.
Update: I noticed some vibration at 28 MPH on a recent ride. It disappeared when I turned the lights off. The vibration is hardly noticeable and much less than I feel on my Surly at 20 MPH.
The nice part of being on the road early (yes, that is light rain falling and yes, I am slightly less of a fair weather rider than I once was):
Lights. Camera. Picture of a dynamo hub: