Both lights have gotten great reviews. The Romisen states it has 150 more lumens, but the HD2010 have larger head. I have not found any beamshots of the Romisen.
Having seen both in action, the HD 2010 will out throw the Romisen. Romisen has better spill, which is not really a desirable feature of a thrower, I would expect run time to be roughly equivalent on the two, maybe a bit longer with the HD 2010 with the larger cell capacity of the 26650. Both seem to do a great job with heat management, but I have not specifically tested that feature.
Romisen is a better all around light, though, being smaller and very bright. They are really quite different lights, not sure it's an apt comparison: which is better should be based on your needs, intended use and what you want.