Blocker,
Your boys are around the same as age as my 3 boys. We are currently going down the pool path. For me I would never have bothered but it is all about the kids. People always reflect on the great memories of when they were kids growing up and doing stuff like swimming in the back yard pool and doing stupid stuff with your mates. Alot of kids of today will have fond memories of sitting inside playing computer games. I dont know about your kids but we have a battle keeping them off the PC's and xboxs when we are home so a pool can only be a good thing. I hope!
Plus it could mean we will spend more time at home on weekends and holidays so I might get some more time in the shed.