Going from an MD80 FO going back to the B737-200 as a captain was a baby step back in technology but even though my 18 months in the MD80 was brief I had to struggle to get by basic flying skills back to what they were.
With the auto everything on the Airbus going to a B757 would be a giant leap. I stayed with the 727 until they were gone and retired in the 757 because it was such a fun airplane to fly. I let the other guys play with the B777. I found my niches.