It saddens me when big respectable names start getting into the "branding" game. I'll assume that the previous posts were correct and that these are not made in-house by sig.
I am an owner of multiple sig pistols (239,220,229) and a very big sigarms fan. A buddy of mine owns the stl-900j weaponlight w/laser. He got it for about 1/2 MSRP from ebay. It's fairly bright and clear, but the UI is pretty...well, let's just say "not tactically sound". Too many manipulations of the buttons are required to do just about anything, in my opinion. Also, the buttons are about impossible to push if you are in a panic state or have gloves on. He feels the same way about it, and was rather dissapointed when he recieved it. As for the other models, i have no experience with them. For reference, i own a p4 modded gladius in a Daniel Defense "pak" offset mount that serves as my weaponlight, and that will hopefully soon be replaced by the olight m30 i have on preorder.