I used this bag for a long time, and loved it. I do a lot of rock climbing so I am pretty hard on my bags too. I was able to carry my D200, 70-200 2.8 VR, 12-24mm, 50mm, SB800, extra cards and accesories no problem. I recently upgraded to a CompuTrekker, so I no longer really use this bag, but I am keeping it for when I shoot climbing because I like having the toploading feature when I am 150 ft off the ground switching lenses, and I can clip it into the wall no problem.....
edit: it might be a bit bulky for you if all you are carrying is the rebel XTI, but if you plan on doing some upgrading and getting more lenses, then this is something you can grow into.