What are the pros and cons of rolled-on wall/ceiling texture paint?
Rolled on texture is easy for anyone who can paint. However, do not get that pre-mixed stuff. It's nearly impossible to get it to a good consistency. Go with the texture additive that you mix in yourself. Just wear some old clothes because tiny bits of the texture are going to shoot off the roller and get on you (more so for a ceiling job). 

All you need to do is pay attention to the texture coverage. Rolling vertical and coming back over on a horizontal to get uniform coverage. I'll do the texture in the first coat then do another coat without the texture to cover up any unpainted texture bits that are barely stuck to the wall.