I've put a Sturmey-Archer XFDD Drum Brake and Dynohub in the front wheel of my RANS Rocket. I was a bit nervous the first time I went down hill with it but now I'm fine. I recently completed a 900km touring holiday on the bike, including bombing down some big hills and the brakes were fine.

I like the fact I have reasonable front brakes in any weather.

BTW I think that proper drum brakes are quite good but the roller brakes aren't as good.