1) That diamond fluting pattern looks purely cosmetic. Doesn't look like it removes enough material to make much of a weight difference no does it look like it changes the surface area to volume ratio dramatically. I'd pass on that type of fluting for any sort of competition.
2) What specific type of competition are you running? For a long distance type, prone or bench slow fire, a heavy contour with a target crown would probably be your best bet, look for match type chambers. For faster run and gun events with higher rates of fire, a lighten fluted barrel with a compensator would be probably be what you are looking for.
Assumption is the mother of all ****ups.
Know what you know, Know what you don't know. -Paul Pedzolt
"Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul