5105 is special denim, but the cuts are impossible unless you are skinny w/no butt. I even sized up and could not make the rise work. My older 2109s I sized up two, which means everything fits, but the waist is loose, so that's the pair I wear when I want to tuck in heavy shirts!
i love the 5105 fit, i think you dont like the low rise? maybe a higher rise is better fit for you? ive got a pair ive repaired twice, its my daily jean. ordering a 5205 now really love the material.