+1 what Don said. Small imperfections in the glass bulbs are the weakest link when they're vibrating and shaking on these old bikes.
I have an LED bulb in a halogen reflector. The LED bulb mimics the halogen beam focus. The halogen reflector has the added benefit of being shallower than the BPF ones. Not only is this a cheaper alternative to BPF LED's, this also allows more room for the wires in the headlight bucket, where space is already at a premium.
I'm a big fan of the stock look (and experience), but this is nice compromise as I can see the road at night now!