Mr. Surfacer spray vs. bottle

Well, one's in a bottle and one is in a spray can.

Seriously, I use the bottled one for filling seams and correcting surface imperfections, and use the spray for texturing areas for a rough appearance for later coats of paint. I wouldn't use it as a primer as such, for that Mr. Surfacer 1200 spray is more suited to.

I think they put it in the spray can for people who don't use airbrushes. Mr. Surfacer can be airbrushed pretty easily, you thin it with lacquer thinner. Swanny has a who how-to on his website, swannysmodels.com