I just shot my new EFK conversion barrel last weekend and it worked great.
It required significantly more than an emery board, however. I was able to use the OEM barrel as a template and just copy the tweaks that they had made with a small hobby file. The barrel would not drop into the locking block until I had removed quite a bit from corners of the 'C' part at the bottom of the barrel.
The fit is better and tighter than OEM and it shoots great to point-of-aim. Some have reported ejection problems but I didn't have any problems running through a box of 50 9mm.