Googled around, couldn't find a head-to-head comparison between the Busch & Muller Ixon Pure and IQ (not the lower power Pure B, or higher power IQ Premium). Anyone had a chance to compare these two?

Both are reasonably priced now and the IQ appears to have the better specs and light pattern, but the Pure has a built in USB charger while still being compatible with AA rechargeables. That's a must for me -- I'm looking for a moderately bright bike mounted headlight that runs on AA rechargeable batteries. I already have lightweight USB rechargeables and need a AA battery light for longer rides (but not ready for the dyno commitment at the moment).