Having driven a Vectra more than once I'd be more worried about a swap the other way! The Golf is an easy car to drive with safe handling, enough power to be lazy with gear choice, and respectable brakes. The Vectra has a steering wheel connected to the wheels with rotten elastic, terminal understeer, uses its wing mirrors to prop it up when cornering, and an asthmatic engine (that isn't very good on fuel either).
Golf - drive it however the hell you want and it'll cope.