I have a B&M Ixon IQ (also from Peter White). I love it and it's a massive upgrade from previous lights (of the be-seen variety, the longer commute required investing in a better light).

I wanted something that didn't have a separate battery pack and this is great-- you just push a little rubber bit out of the way and plug in the wall charger. I charge it every night so I don't have to think about did I charge it last night? two nights ago? etc, but assuming the battery indicator is accurate I could easily get 4 commutes out of it (~4 hours on the bike) with a mix of high and low settings. I try to run it on low most of the time, high is pretty bright (but good for dark MUP).

I also run a blackburn flea on flash most of the time. Good for be-seen, and also easily rechargeable.

At some future point, I can definitely see the appeal of a dynohub, and if/when my front wheel meets an end I may go that route.