Since nobody else has, here's a study I found: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5406732/
I don't love the study, it's only 156 patients and boy do they have some large error bars on some of the numbers, but it should still give you a rough idea of what the reality is. In this study, the incidence of staple line leakage was 1.2% (2 patients), the incidence of staple hemorrhage was 0.6% (1 patient), incidence of GERD was 15.3% (24 patients), hiatal hernia requiring surgical repair was 0.6% (1 patient), and conversion to a gastric bypass was 0.6% (1 patient).