I own 1 custom bike, and i'm to lazy to list parts
I personaly don't like the look of them, also I feel that they are not needed. If you just buy a good chain like the Shadow half link, or the new S&M half link that's sapose to be comming out soon, you won't need one.
my freind has that exact same chainwheel in 30t, he likes it, and the only complaint he has with it is that it doesnt fit his 22mm spindle on his new Primo hollowbites AND for some reason his Shadow chain has messed up the inside wall of the "gaurd" part, because it didnt fit too well when we installed it, so if you decide to get one (despite what beerman said about how you dont need a gaurd if your going to have sucha small sprocket) then dont plan on getting the Shadow chain or any other chain with half or bigger links...
oh and as far as keeping pants out of your chain, it does work for that, but then again, so does having a smaller sprocket...
I havent had any trouble with my chain as far as riding it, but getting it on with those weird links is hard, (I broke 2 chain breakers while pushing the pins into it), and as for the pants gettin caught, i use good ol' rubber bands...(tight pants work well,along with girls pants...)