The duramax has soo much torque it was wrecking the manuals.
I do not drive for a living but towing my boat thru the PA mts. and my dump trailer using the '06 allison in manual mode is fantastic. I almost never have to touch the brakes. When I fish the NJ shore I end up coming up thru the Blue Rt or "SureKill " expresss way towing my Whaler.Tough roads as most of the way is only 2 lanes. Just push the tow haul mode button and I 'am not getting cut in front and can deal w/ the short stops/fast start ups that come w/ an outdated highway.
I drive stick, learned @ 11 yrs in F350 SA wrecker ,driven many since, but I feel the Allison is overall a better choice then a stick.