I have the MK II in 5.5" and a MK I w 6.88" - and the 5.5" bull barrel is much better balanced and handles better in rapid fire as well.
VQ makes a great grip for one handed Tgt work but this requires an extended mag release. I have had "issues" w reliability when I put the two together. No idea why ? Have talked about this w VQ and they just sent me another mag release.
Note: I removed both and the gun is harder to control one handed but at least it is once again, reliable. Old 1911 problem - aftermarket parts are not always your friend.