I had a similar reaction to the OP when first driving our new RAM CTD.
When in cruise, the down-shift to 5th is loud and busy, as cruise waits for the mph to drop ~4 mph, it then races to catch up and revs the engine upto ~2500 rpm, before settling down to a comfortable 1800 rpm in 5th. This prolly what I least like about our RAM CTD with the 68RFE.
But there are a couple of options to avoid this:
The simplest is to stay in cruise and lock out 6th as soon as you hit the hills. This is what I and most others do.
Or you can manually downshift to 5th. The transition is much smoother with no high-rpm flare if you downshift at the base of a hill before the mph drops. But it's too much trouble for me, especially on long trips in the hills.
