It's not direct drive (there's a driver in it) and it'll run for almost exactly 35minutes on a protected RC123. Also the HAIII front and rear are 2 different colors.
I put a 16mode driver in it because it has a group that only has Hi-Med-Lo. The runtime on Med was 3+ hours. I have a Q5 that's going in it soon and I'll revise my runtimes then.
Overall it's a nice light but unless you NEED HAIII I would save my money and go with the Romisen version. They make a good product and the price is right.
If you want a light with multiple modes and longer runtimes you should consider:
http://www.dealextreme.com/details.dx/sku.10806
It's the same light just with a clicky, 5modes, no clip, and a Q5...at $18 it's a steal.
Also, depending on how much you want to spend you can't go wrong with a
Fenix Q5 P1D-CE