| i tow 7500lbs trailer all the time for work and the duramax does a assume job, i do use the T/H mode but if i forget to turn it on i don't realize it until it comes time to stop, the aggressive down shifting from the allison trans makes a huge difference in the amount of brake required. T/H mode on the up shift side just holds each gear a little longer for aggressive pulling once you are out and moving it makes no difference, i also leave my OD on unless the hills become to much and the trans is making constant down shifts to maintain current speed which does not happen around here (the inclines are small and my trailer to lite) | 
Linear Mode
