For what it's worth, a description of the 2005 TorqShift transmission behind our 2005 V10 would read almost the same.
The 2005 TorqShift computer controlled transmission also has 6 speeds - but the driver can directly invoke only 5 of them ... the transmission control module chooses between 2 ratios for one of the gears internally beyond driver control, depending upon certain conditions. The newer TorqShift may allow the driver to manually select among all 6 gears when appropriate - I'm not sure. Our Tow/Haul mode works the same as described above
That being said, the V10/Torqueshift combination is all around superb. You do have to get used to driving the combination to fully tap their capability, though - especially how to counter-intuitively use the V10 as a high RPM engine - which was rare in a truck prior to the V10 and different than the good old thumping V8's many of us were used to in our daily vehicles of old.