I got my protac backrest a few days ago and what a world of difference it makes.  Just mad I waited as long as I did to get one.  I wasn't real impressed with the mounting bracket though.  The paint flaked off easily when I tightened the nut down and I can still move the back rest back and forth without much trouble.  Also there are no set screws to hold the rest into the mounting bracket.  I guess the brackets are the only problem I have with it.  For 120 clams I expected the whole package to  be quality work.