I have a Hot Tamale ("miniature" - 18" to 30" - http://www.helpmefind.com/rose/pl.php?n=1900 ) in the gritty mix and it is performing quite well. It overwintered indoors and is at least 30" and still pushing new growth.

Last year I grew productive tomatoes and peppers in the gritty mix as well. You can grow anything you want in the gritty mix. It all depends on how often you're willing to fertigate to keep the plants alive. If you used granite as your ballast then you could certainly put a full sized rose in a 16" pot without fear of it blowing over. Then the trick is to keep it watered.

You should think of the gritty mix as manual hydroponics with a buffer. The Turface/Axis might give you a day, or maybe 3-5 days depending on the plant, weather, and the size of the pot. My large citrus trees will wilt in the summer heat (say 90+ in full sun) without twice a day watering in the gritty mix.