I have some self modified XR-E LED torches (with modified Li-on battery packs - I can power two torches from one pack for example), some cheap 'flashers' just to get me seen, and a T6 Bike light. (I have also used a P7 bike light).
By far the best for spread and useful light has to be the P7. The XM-L T6 simply has too much of a spot and not enough spread. Brilliant if you want throw for viewing things at distance, but bad for general lighting for my usage at speed. Don't get me wrong, I like the XM-L LED I just feel the better bike light is the P7. I will be experimenting with different reflectors sometime soon.
Don't screw around with cheap cack batteries like ultra/sure-fire, get decent li-on that are reliable and give close to the rating they provide.