It's all about your viewing habits. I moved from a Infocus 7210 DLP projector + 77" screen to a 73" 73640. The move from 720p to 1080p was nice, the move from having fan noise over my head to fan noise I couldn't hear when the program was playing was nice, and the move to be able to actually use the TV during the day without going around and blacking out all the windows on the floor (open design main floor) was nice. And as much as the LG LST-4200A ATSC tuner was great, it was old, and the ATSC tuner in the Mitsu was a great upgrade.
So the move from a "TV" to a projector is more about do you want a theater feel to the look and usage of the environment, or more or a TV in a normal house room look and feel. If it's dedicated light controlled environment where you'll go lights out mostly, I would think projector would give you better screen options. My 73640 definitely has a lot of dimming of the far top and bottom as I stand up / sit down vs my old matte white 1.0 screen. Both are/were fine at large horizontal angles, say off in the kitchen to the side making dinner,, but the Mitsu screen view is more impacted by vertical change than my old projector screen.