NO problems after years of use.
I have owned a Bison GT for 2 years...NO problems with my unlocked phone on mint mobile, straight talk, ATT or T-Mobile. I drop it and then use it for phots and talking. I agree there are no updates to the latest android version. I go to You-Tube for work arounds where needed. As critical as i want to be, this is a EXCELLENT phone. I have owned big brand names.SO, i am buying the latest UMIDIGI for a granddaughter in college.