I'm a big guy and want to buy two seats to be comfortable on an upcoming Delta flight. I'm fairly certain that the legs of my trips that involve 757s won't be an issue as I've read that their armrests are raiseable. I've read that might not be the case for some and possibly all seats on CRJ planes. I've checked seatguru and seatmaestro, but they have no specific information on raiseable armrests and their seating chart maps for CRJ-700 and CRJ-900 don't match the charts I saw when doing some preliminary research at Delta.com. Thanks for any information you can provide.