RE: broadhead choice help needed please!
If they both shoot well with your setup, then either one should be fine. a well placed shot will be the best way for a good quick kill, and good blood trail, and is more important than the tip on the end.
Both these Broad heads have 1-1/8th" cutting Diameter, so I'd suggest the mx4, simply because you have the extra blade...one more cut should equal more blood...either one will perform just fine, as long as the shot is good, and neither one will make up for a badly placed shot.