I just purchased the MX 3 last week and only had to move my sight up a smidge. Shooting sweet as pie out to 50 yards. I shoot a Guardian with an Easton 400 that is 420gr fully loaded with standard fletch. I did not align the blades with the fletchings and they still flew great.

I shot my 3d arrows with 2 Blazers GT Hunter xt's decked at 380gr and flew slightly left...but still more accurate than my old standard Muzzy 4 Blade.

I assume the muzzy mx 4 will fly much better than the old ones. I have found once you get to pushing your speed over 280fps that the older4blades need be tuned to perfection.