I haven't even changed mine out for the first time. Coolant is usually good for 5 years/100,000 miles. I will do mine next winter. I don't bother spending extra money like this. It's like changing the oil at 3000 miles. I do mine once a year, since I only put on @ 6000 miles/year on it. Money down the drain and I doubt you get any benefit from it.
I agree with that. I don't know why Honda calls for such frequent changes when similar auto engines with identical coolant can run 100,000 miles on the original coolant.