Anyone have any experience with this product, specifically the durability of it and easy of application.

I've posted before about my Salsa Alternator dropout slippage, which has improved greatly with the maxle and new 142x12 dropouts.  The more rigid connection has helped, but it's still not fool proof.  One thing I've seen is that the paint where the locking bolts contact has been scoured clean along the range where the bolts have slipped.  Clearly the steel on steel friction isn't enough to prevent additional slippage.  I was thinking about dipping this section in a couple of coats of plasti dip to cover the bare steel and to provide some added friction of steel on a rubberized surface and wanted to get some thoughts on this product and this application.  Thanks!

Take it to a machine shop and get them to knurl the surfaces. That'll hold it.

I have used plasti dip for a few projects. It's very thin and will peel off fairly easily. If it's not being rubbed or handled it will hold up quite well. It will not hold up to any physical contact between parts.

Use valve lapping compound to provide some extra grip; you can find it in small tubes at the auto parts store.  It's very similar to the Finish Line Fiber Grip assembly lube that keeps carbon fiber bars and seatposts from slipping in pinch clamps.