I know what you mean, they can be a PITA too, as soon as you fix one thing, something else breaks on the test drive lol.
The cooling system is fragile and well worth doing - actually one thing I like about the M52 is how easy it is to get to the alternator, tensioners, water pump, fan, cooling hoses, radiator, thermostat, coil packs, spark plugs, throttle, maf and airbox. It could be a lot worse but thankfully not.