no chain guard for me , no chain oiler to fling oil all over the back end ,
MCRider got it right like my steel finish chain looks better without the gaurd and in keeping of how I want the bike to look ,
Still,it just looks unfinished to me, to not have some kind of guard. Even with an X-ring chain you'll need some little bit of lube, chain wax, etc. to lube the chain/sprocket interface. And where there's grease, there's fling off.
For me, there's that. A minimalist guard is appropriate. With the proper design and finish (Chrome, polish, powdercoat) it should be an enhancement.
And if you're ever taking it to the drags you'll need one to pass tech inspection.