So I haven't tried AR yet, but I do know it has a laws-of-physics limitation - it's impossible to draw black on the screen. Basically, you can only make things brighter than the background, not darker - so if you're already in a bright world, good luck seeing anything. Subtitles become impossible unless you're in a black/dark room because you can't draw black borders on the text, and just outlining things in general (so you can see them) is essentially impossible.

http://blogs.valvesoftware.com/abrash/why-you-wont-see-hard-...