I have found this to be great sling...
As with everything in shooting we all should make cheaks on our kit everytime before shooting, with having a gemini butt plate this has been a must as bolt/screws do work loose, so the mec sling is no exception.
One time when going through my cheaks I found one screw half undone so that was soon tighten and when cheaking all the others one or two were also loose, but now with cheaks in place I have had no problems.
As for the ball bearings on the screw-in part on the sling loop that was taken care of because I cut that part off, because the Mec loop is a little bigger so would not fit into the Gemini handstop that I have.
I replace it with a Gemini loop which is a little smaller and just butchered the old Kurt Thune sling I had for the screws,the KT sling had seen better days and I was not going to pass that onto anyone in that state!!!
By folding over the strap then fix in place with two screws I had only lost around 2 inch's of strap there was plenty that I was not needed anyway as I had cheaked that already. So then just took all the others scews out of the KT sling for spares just incase I did loose any from the Mec sling at anytime...
Its the boy scout in me I suppose!!!
I find the small pully wheel ajuster to be of great use with firing point levels being different as we all know many are!!!!
And with doing Any-sights comps this small ajustment is worth its weight in gold, while in position you can soon make ajustments to sling tension...I have had my Mec sling now for about 3 years and have been very pleased with it....Mark