C90 is a fantastic aeroplane, but the B200 is the better one by a long way.
But old Kingairs are maintenance intensive, once over the 10,000 mark you will be needing deep pockets and good engineering support.
The Norfolk Kingair trend monitoring is nothing short of legendary, endorsed on the B2O0, then endorsed on the trend monitoring and don't deviate from SOPS.
The chief pilot and chief engineer must have been a fearsome combination!