Just remembered a few more bits and bobs if anyone is interested.
The overhead panel has been tidied up a bit. The engine start panel is simplified, no more manual start or continuous ignition switches, the whole thing is automatic. The engines also monitor absolutely everything and shut themselves down if they don't like it. The 400 (CF6) only monitored Hot, Hung and no EGT rise.
The engines take longer to start than the CF6 (can't speak for the RR) and tend to vibrate due to rotor bow. They also produce quite a lot of smoke which alarms the ground crew. This is normal. The engines themselves look the dog's bo****ks with large scimitar bladed fan blades. So far they have been very reliable. Take off requires 40% to be set prior to pressing the blast off button. The ground anti ice procedure is a bit different and you need to watch vibration levels. Any more than 4 and you have to manually de ice the engines. Not been a problem so far, even in a frozen ORD. A PIP from GE is expected at some point to address some minor issues, including the smoky start.
There is no more Aft cargo heat switch, it is incorporated into the system elsewhere and the yaw dampers have to remain off until the IRS has aligned. The pack selectors have been replaced with simple PBI's.
That's all I can remember without looking at the manual and I'm on days off!