I've had BT-20 on my VFR and that front was scary as hell, cupped really early. Replaced them with Michelin Pilot Road 2s and it transformed the bike.
The Versys came with BT23 and they were much better. However, the front cups pretty bad too when worn, but it does not provide the scary feeling. Wearing both of them pretty flat in the middle after the last leg of the last trip was through deserts and Montana makes it for a heavy steering bike, but not unstable feeling.
So, while BT23 is ok, a new set of Pilot Road 2s goes soon on this bike as well.