Proactively replacing cooling system - anyone doing this?

[thebluedog]

Hey guys - I was curious to find out how many X5 owners have proactively replaced their cooling systems. If you have, what did you replace and at what mileage? Costs? Or, if you haven't, do have 90k miles or more?

BMW Expert Mike Miller (from Roundel Magazine) recommends proactively replacing the cooling system on these 6 cylinder engines:
M50, M52, M54, S50, S52 (US-spec)
Lucky for us M54 owners, we made the list!
*Every 60,000 miles: water pump, thermostat, plastic thermostat housing if so equipped
*Every 90,000 miles: radiator, expansion tank, fan and fan clutch if so equipped

I've got 63k miles now was hoping to replace the complete cooling system at 90k miles or 2 yrs from today. My local Indy charges $1500 to replace everything. I just spent a large sum of money on the new belts, fluids, new axle assembly, and soon Inspection II, so I'd like to defer my costs, but don't want to risk my engine due to overheating.

Thanks!