I'd suggest continuing to use your SuperNova but supplement it with a bright battery light to use in situations where your night vision is compromised by other lights. Lots of vendors selling nominal 1200 lumen (prob. really 600) with Cree XM-L T6 LED such as:
http://www.amazon.com/CREE-Bicycle-H...3310617&sr=1-6
for about $25. They run about 3 hours at high power or all night at the low power setting and can be either handlebar or helmet mounted. Having the battery light as a supplement to the dyno one also gives you redundancy if any problem should develop with either light.