Bosch gen 4 vs 5 (buying advice)

Looking to get my first ebike. I live in a northern Europe and have tested a bike with the gen 4 Bosch Performance CX.

However gen 5 just released.

How big is the difference? Software updates etc?

Worth paying €500 (or more) for a gen 5 bike or save money and go for the old gen 4?

Cube for example offers both versions still.

TIA