One "side effect" is the added CPU power necessary for it. Other than that, I don't know of anything. Stats like detection range have been modded so that they work with the mod, so that's not an issue (not only can
you see longer, your watch crew can, too
).
As for where to find it, I don't know. Bah, just download
Grey Wolves and the 1,1 patch and it'll be there. It's a very good mod, worth the download.