I don't run a tail light & run one 35w bulb. Been running it for about 6 months now, no problemo. Did one night ride (pitch black, way cool fun) - only hassle was not being able to tell where the trail went when I'd come to the brow of a hill. I also attached a glow stick so if I dumped it & the bike stalled, I'd be able to find the bike. I'd done a night ride with the stock headlight & wasn't impressed.
It depends on what you want the headlight for as to whether to get the coil rewound or not. For my one night ride a century, it's not worth it - I use it more as a marker for illegal riders - maybe they'll see me before I have a head-on while we're marking out trails. It's also a good way for the guys to see if I've still got the bike going or not (it's been hard-wired on, as someone broke the switch, which always got full of crap & wouldn't work anyway).
Hope that helps some