Blu-Ray vs. iTunes 1080p

I've been selling my DVD collection. It's just gotten to the point where it's too big a pain to deal with accumulating physical media, especially given the number of times I've moved over the last several years. (Ah, the glorious life of a student.) I've been replacing the discs I'd discarded with HD films from iTunes. Generally speaking, it's a good arrangement. But some films aren't available on iTunes in 1080p. Some films aren't available on iTunes at all. But they are available on Blu-Ray. I'm not going to tell you that iTunes 1080p movies are better than Blu-Rays in terms of picture or sound quality. They aren't. Period. But in most cases, they're close enough.

So here's the conundrum. If a film isn't available on iTunes in HD, is it better to get the film in SD on iTunes or buy it on Blu-Ray? If a film is available in iTunes in HD, is it visually spectacular enough to justify the minor inconvenience of getting it on Blu-Ray and thus having to deal with a physical disc (and the accumulation of physical discs)? Which films are worth owning physical copies of, or is that in and of itself an outdated concept? And with some Blu-Rays cheaper than iTunes films, how is the consumer supposed to make any sense of this all?

Thoughts?