Questions come up about stripes about every month or so. I can only tell you what I have experienced.
I have purchased from two venders, Ridergraphix and Revolution Motorsports. The materials have been 3M Brand and Avery Decals. I also see absolutely no difference between the Avery decals and the 3M decals.
The only difference between Ridergraphix included instructions and costs nearly 3x as much and with Revolution Motorsports, stirpes were 1/3 the price and all you get is the stripes, no directions.
Since I take my car to a professional to install, the last set of RM stripes worked perfect for me. If you use a professional, check them out first. The place I take my car has extensive experience with decals, had numerous awards posted as 3M's Regional Award winner. Both vendor's stripes fit/finish are perfect.
I got to chatting with the installer after the last visit and he said they also cut decals and that all vendors buy the same 3M and Avery product, and said that at $110, RM was still making a "very good profit." You can imagine what RiderGraphix is making?
I have had both sets of stripes on for over a year and not problem with either vendor. Both venders are challengertalk supporters. In the end, you have to do what best fits your situation and allows you to sleep at night.