I guess each area is different. I am not far from you, but in a different type of locale (rural vs suburban). So the ROI will probably be different for you than it is for me.
You are asking the same types of questions I was a few months ago when we were thinking about it. Bottom line, if you are going to be staying in your house for a long time and you and your family really want a pool (and you can honestly say that you will use it), then I say go for it. Is it a "smart" investment? Absolutely not. I'm building ours with the knowledge that most likely this is not going to come back to me. For us, it isn't an investment monetarily...but more of an investment in our lives and in the enjoyment of our home. We already spend a LOT of time in our backyard as it is, even with just grass. So to us it is worth it.