I'm so glad you asked this question. I don't know why but sometimes parents of "easy-going" kids feel guilty for talking about it. As if we have to find something to gripe about so that other moms won't hate us. I feel this way a lot, and sometimes I say something negative (even when I don't find it to be a real problem - like "my son being so rough when he plays sometimes", when actually he's just a happy, boisterious, imaginative child who is so sweet and considerate - and just being a little boy. He's 3.).
I don't know if my kids are easy-going by nature, but I think it's mostly because of training. The gift that I got from them is that they have always been teachable. So any problems with behavior was always fixed through teaching and training. They have always adapted well to changes and are very friendly, well-mannered kids. Everything I did with my oldest (daughter), from feedings, sleep-training, disciplined, and academics, she has excelled. And I see the same with my son. He just turned 3 in May and he has already learned to read 3 to 4 letter words. Actual reading (phonetically sounding out the letters and putting the sounds together to make the words - not memorizing "picture words"). I can't believe my luck at how teachable my kids are. Even training my kids to love each other, play well together and be gracious to one another was doable. And they are all these things at the tender age of 5 and 3.
Thanks for letting me brag about my kids, I never get to do this. REALLY. NEVER. The moms I hang out with would consider this as being a show off. It's always trying to find the hardships in parenting that I feel most of my conversations with other moms are usually about - conversations that are considered more acceptable.