It's really a hard decision to make because each person's response to the surgery is different. I had Roux-en-Y surgery, but that was more than 15 years ago, and I had an open procedure--major surgery--because laparoplasty (sp) was not yet available. But It worked amazingly well and fast, with 35 pounds gone the first month. After losing 75 pounds in 3 months, I plateaued for a few months, even though I was still eating less than 1000 calories a day, based on my post-op diet. I broke the plateau by taking up hiking in the mountains. So, the surgical procedure may be less important than your commitment to diet and activity after surgery.
I'd search the group and look for posts from members who've had both procedures and pay special attention to their level of activity after surgery. Even then, you can only guess how this might affect you. As Missy wrote above, let your surgical team help you make the decision, based on how much weight you need to lose, how committed you are to doing what needs to be done to reach your goals and your blood tests and psychological profile. The surgery is just one cog in the wheel and both will probably work for you.
Congratulations on making your decision to have the surgery. I can tell you for sure, I'd do it all over again in a heartbeat, because it is life-changing.