Yes, laminates on canvas always look hazy to my eye, especially when the light is coming from behind my head as when looking at a print opposite a light source like a window.
Coatings have less of this, possibly because they conform more to the irregular surface of the canvas whereas laminates are rather planar on top of the canvas.
And in general laminates look and feel sort of "plasticky" whereas coated canvas invokes the sorts of textures one sees on paintings, even when not deliberately textured. Scratches on laminates are more damaging than on coatings, and scratched coatings can be repaired at any time with one more coat or even a local brush application.
Coating is very easy with a decent HVLP gun and a reasonable place to do it. I tape up a bunch of canvases on a 48x96 foamcore and give it 3 coats about 20 minutes apart. Each coat takes about 5 minutes max.
Most canvases take water based coatings. The only real case for lamination over coating is for those few canvases that require solvent coatings, in which case lamination is a nice alternative to brain damage and vapor explosions.
You can also roll on coatings, but IMHO it's a mess and invites dust and just doesn't work out a lot of the time.