Three or four years ago, I purchased a NW ticket SEA-MSP-JAX and return. A few weeks before my trip, I received notification of a schedule change; imagine my horror when I discovered the mainline jet on the return JAX-MSP segment was now a CRJ.
(The current NW schedule shows this as
1174 miles, 3 hr 21 min. block to block on the A319 – so probably a wee bit more for the CRJ).
I called the PE line to revise the itinerary. I explained flat out that 3 hours plus was unacceptable on a CRJ; the agent responded the only reroute he could offer that same morning was a mainline jet to DTW with a 3.5 hr wait at DTW – the agent was flabbergasted that I accepted this – I informed him that waits like this were why I buy 3-year WC memberships. It all turned out well.