I've owned a Bis for some years now. It has been quite reliable, apart from the loose coupling episode. No overheating issues.
One other advantage the Bis has, is the heating system. It is superb!!!! Also, personally, I think the Bis engine is quieter (though still noisy), and a bit faster as well. It has larger wheels, so also smoother. It has nice small touches over and above already mentioned (hatchback etc.), like intermittent wipers, halogen lamps, headrests (later Bis models) et al makes it easier to live with.
I've got a 1990 aircooled.
Can't disagree with the heater, mines rubbish and stinks of oil:p
However I do have factory intermittant wipers and headrests and I bought some halogen bulbs which plugged straight in. Mine also has front and rear retractable seat belts. Maybe because it's an export model? Not sure.
I like my aircooled but there are no watercooled models here at all so I've never compared them. A hatch would be nice though!
