Methinketh you should re-work you lens line up.
24 and 30?
15-85 variable aperture. 7-2/4. Why not ditch the 30 and pick up an 85/1.8? Or 135/2? Since weddings in low-light environment seems to be a significant part of your repertoire, you might as well shoot w/ the right lenses.
Shooting the 7D w/ 15-85 would be similar to shooting with a 5D2 w/ 24-105/4. That's not really the "go-to" zoom for most wedding photogs I've seen.