All the BMC C-Series engined cars such as the A90/95, Isis, Marshal and Wolseley 6/90s were demonstrably quick and they were ideal for Australian conditions, particularly in the bush. One reason the Isis failed was because it looked too much like an Oxford when the price was substantially higher. It's easy to be dismissive of these cars because they didn't have showroom appeal, but having driven plenty of A90s and A95s, I would imagine the Isis to be similar. It was roomier in the Issigonis tradition than the Austins and well appointed. This pic is of the Series II where they changed the grille.