I am about your size and paddle a Jefe. I am 6'1", 170 and the regular Jefe fits me perfectly. Maybe I could paddle the Grande, but I don't really see why, because the Jefe floats me high in the water even with an extra 10 pounds of gear in the back. One of my favorite things about the boat is the fit. It feels long and floats high, but the deck is low and out of the way, so it doesn't feel like paddling a tank. If the Grande is similar, that might explain how some small people paddle such a big boat.
In terms of rolling, it is kinda hard to roll. I am normally of the school that if you can roll one boat, you can roll any boat, but the Jefe is kinda hard to roll. It just doesn't seem to snap up crisply at the end, if you know what I mean. That being said, if you have a solid roll, it shouldn't be much of problem. Just don't drop your paddle.