I was 3 years post op in September of this year.
As far as physical side-effects, I've had a pretty smooth journey. My B12 was a little low at first, which is pretty common. I had a couple of monthly injections for that and fine since then. Around 2.5 years post op, following my Tummy Tuck, I became severely anemic requiring blood and Iron transfusions. We can't say with certainty it was because of the sleeve , and honestly I think it was related more to blood loss during the tummy tuck surgery. That was probably the most serious of the complications. The only other thing was loose skin, and I was able to get my panni & TT covered by insurance for that.
Positive side effects abound though!