You have the right impression! The 3M is a lot harder to stretch and work with in general than the XPel Ultimate Plus. I started with the 3M and used it on the bumper and mirrors. I was not happy with the outcome. Keep in mind, I'd never touched PPF before trying to wrap my front bumper with it. Don't start with the bumper! Start with something easier like a fender...
I have since switched to XPel Ultimate Plus and I have decent skills stretching, aligning, trimming, and wrapping PPF in general. I was very pleased with how my fenders and hood came out, so I peeled and rewrapped my mirrors using the hot water trick to get a lot more stretch. My biggest issue is my garage does not have a very high ceiling and it's not very clean (despite cleaning it). I've found a few bits of lint or dust got under the PPF as I was applying it. I know the car was spotless at the time, so I think the contaminants come from the air that moves while peeling the backing off the PPF. It's not much different from installing a screen protector on your phone - any little thing that gets between the protector and the glass makes a small bubble. Once you spot it, that'll be all you see...
I plan on wrapping the rest of the car in the spring, but I may just rent a storage unit for a month so I can get a clean place to work without shelves, dust, and spider webs hiding in every corner.