I heard both sides also. I went with the Diff at first. The first wall I did seemed to go fine. Then it got very tiresome. I ended going to HD and buying a Wagner steamer, sells for under $50. That's what I use now, much less mess too.
The key to either method is scoring the paper. That way the steam, or stripper, can get to the adhesive.
Pick up the trash as you go. Otherwise you'll finish, and have a big mess to clean up, when you just want to go to bed. It's amazing the volume of paper that will come off.