I'm three years out and prior to surgery, I had a BMI of 50. My surgeon recommended the sleeve because I was still young-ish then, e.g. early 30s and nutrient absorption is pretty important. My surgeon felt that the calcium/vitamin D malabsorption may lead to bone density issues later on in life (and after obesity, people generally don't have great bone density and are prone to fractures). Most of bariatric surgery is relatively new, so there aren't a ton of long term studies, so my surgeon is just guessing. And most people on the bypass seem to be pretty good about taking their vitamins (which is something you should do with the sleeve anyway).
A couple of months after my sleeve I was diagnosed with a range of painful, chronic autoimmune diseases and I'm very thankful that I went with the sleeve because of the issues with drug absorption with the bypass (I have to take a ton of oral medications). Of course, I did not deal with GERD, which means that the bypass is right for many people.
With the sleeve, I was able to take my BMI from 50 to 25. Due to aforementioned illnesses and medications, I did deal with some regain, which I am slowly working on. At the moment, my BMI is about 29. I have never felt like the sleeve wouldn't be enough to help me achieve success.
All that to say, you can definitely have success with the sleeve or the bypass. As commented by others, a lot of it is going to come down to what your level of commitment, and your ability to change your lifestyle and deal with psychological issues. And you have to educate yourself. You can't drink a diet of only protein shakes forever. At some point, you have to learn how to eat real food in the real world, go to work, socialise and interact with food, people and life. If you haven't dealt with your "issues", you will have regain with either surgery.
It can be a tough decision, but I honestly feel that you can find success with either surgery.