Got a projector for the living room a few weeks back. Tonight I decided I was fed up waiting to get through TOS before watching the movies and so stuck on "The Motion Picture".
It's slow, ponderous and has huge stretches of not very much happening, but I still mostly enjoyed it. Part of me quite liked the slowness of it. Modern movies are so fast in how they play out that it's actually quite nice to have something that doesn't fly through the plot.
It's very much an extended episode of the show, but you can tell that a huge portion of the budget was spent on the effects and models used (I think they re-used large amounts of model shots in subsequent movies). It's visually stunning, though the famously masturbatory Enterprise reveal scene does go on a touch too long.
Having it on the projector definitely helps with the spectacle of it.
It's quite telling that when the credits roll the first three names listed are Effect Supervisors.
So yeah it's not a movie you'll rush back and watch multiple times, but I do think it's decent enough if you can handle the slow pace.
Looking forward to Wrath of Khan though.