Lumen ratings are very innacurate. Many chinese manufacturers say that their cheap P7 have 900lm. It's bull..it. 900lm is max for P7 - properly driven and heatsinked. Actual current to emitter varies from 1,8 to over 3A. Real brightness? 400-800lm...
I noticed a new batch of them today at a particularly 'extreme' website. I'd post a few links, but that seems to be a no-no here.
Anyway- there are a couple that look interesting. I don't want any blinky, disco modes, so that narrows it down a bit. And they all seem to run a little low on current. Is the MC-E not able to handle as much current as the P7?
Or is it just a heat issue?