We covered the differences mostly during the transition training from 400 to 800.
The first things comes to my mind starting mulfuntions like with the use of battery(APU shutdown during start) the captains instruments and engine instruments are still available,if you forget to put the engine gens on line and take off with apu on the bus,even if you shut down the apu for one time eng gens automatically switches on bus,there are differences with engine instruments(as they now announce failures,starter assist,fuel inbal etc.)
I also remember we had TCAS TA/RA's since our 400's have Tcas installed on VSI.and NG displays it on map.(ours are EFIS/MAP not PFD/ND)
There were also DU mulfuntions,and some mulfuntions like Display source,EEC,PSEU.
Its been a while so these are the things that I remember but not all.Good luck on your sims.