I have to admit, if you don't read all the posts, it can get pretty nutty trying to find out the best performance light, of any type.
Try getting more specific in what you want. Size, cell type, finish, switch type, location of manufacture, modes, beam pattern, etc.
It really is quite nuts. I still think search would have saved a lot of hassle, but I guess you need to figure out what you want in "overall performance".
Read through a couple threads of the same type, just try it for a bit before posting.
Like these:
http://candlepowerforums.com/vb/showthread.php?p=2233421
https://www.candlepowerforums.com/threads/171086
http://candlepowerforums.com/vb/archive/index.php/t-167435.html
This kind of thing shows up when searching for keychain.
You can then narrow it down more, using certain brands/models, or battery types.
You know, start at the beginning, get more info, then post if you need more info.