I used one all last winter, and am still using it.

I had one problem; I assembled the thing myself from parts, and at the time BatterySpace said that their 14.4v bottle battery was "perfect" for this light. It's not. The HID specs a max voltage of 14.8v. A 14.4v NiMH pack puts out over 16 volts for a long time when freshly charged, and takes > 1 hour to drop below 14.8v. I wound up frying the ballast in my first HID. Fortunately TrailTech fixed it for free.

Now I'm running at 12.4v (regulated, didn't want to hack up my 14.4v pack). Many hours since then, no problems.

If I were doing it again, I'd probably go with a 12 or 13.2v pack, or maybe LiIon. I intentionally stayed away from LiIon last time because I often ride when it's < 10*F and LiIon doesn't do well at low temps. But I think for those few times I could put the pack in my jacket.

I actually have the Spot. I ordered the flood but they misshipped. They offered to replace but I decided I didn't care that much. I think I'd get the flood. There's plenty of light to spread around, the spot isn't needed.