I found this size comparison between the FC11 with a short tube and the Sofirn SC21. I was about to get SC21, but I like 18350 standardisation (Sofirn IF19) :-).
Incidentally, I discovered that Sofirn SC31 seems similar to FC11, at least visually. But it appears that the new FC11C may be the overall winner in light quality, portability, and usability if a long throw is not needed or desirable.