I tend to see a UST projector used in a family room type of environment, where there will often be lights on, reflective walls, etc. It basically provides a relatively easy way of getting a fairly large image in that situation, vs having a large TV, which is more limited in maximum size, more cumbersome to install, etc.
But if the goal is recreating the theater experience at home, with the emphasis on movie watching, in an at least a somewhat more dedicated environment, a traditional projector like the JVC, would be better suited to that task. And if the room dimensions allow, and if movies are important, I always encourage going with a 2.35:1 to 2.40:1 aspect ratio screen, since perhaps 70% of movies are in that aspect ratio.
I'm sure there will be exceptions, so these are not absolutes, but at least at this point in time, this is how I would approach that decision.