We love our pool. We live in PA, and use a heater. I keep the pool warm. This early in the year, I like it close to 90 degrees, DH jokes that we have the world's largest hottub. It is not even May and our pool is open, and will stay in steady use until early September when the kids go back to school. It is not much work, if you USE it all the time, it rarely needs swept, all that swirling water lets the filter do it's job. We have an 18 X 36 with eight foot (i think) deep end, diving board and slide. I teach, and have the summer months off, so I have plenty of time to watch the pool and enjoy it. Dh installed the pool himself, buying a kit from a local pool store. It was very inexpensive, so we added all the extras like the slide, dive, extra concrete decking on all four sides.
We have guests most every day during summer. My rule is: no kids without bringing an adult. I am not an unpaid babysitter for the neighborhood, but I enjoy when friends come to swim and I have another adult to talk to. The second rule is: All kids must go home before DH gets home from work. He does not enjoy coming home to a gaggle of kids. I don't mind it (elementary teacher). DH is a redhead and doesn't like to bask in the sun, but in the evening shade he will enjoy a dip with our own kids.
If you have boys, they will definitely rough house and fool around, a lot. This doesn't bother me, but we go through inflatible pool toys really fast, especially when we invite the ball teams over after a game. THe girls tend to play calmer games, like "judge the dives" or "beauty shop".
I like knowing where my kids are and what they are doing, I am a constant presence and know all their friends and the parents as we chat poolside. This in itself is a huge positive to me.
We have a poolhouse with bathroom, which is great because no wet feet and drippy bodies come inside my house to pee! I have an old refrigerator/freezer out there, too, and keep it stocked with popsicles and drinks. The kids think it is insanely cool to eat popsicles while the float around on the pool toys. Yes, I go through a lot of snacks, but I find most "guests" will bring a snack to share every time they visit (do we have good friends, or what!)
For me, the pool is the best thing we ever added. Ours is 12 years old and the liner is faded, and will need replaced this year. This will be a big expense, but well worth it. Heating costs, but the pool gets used for hours every day. Unheated pools in PA are not practical, we knew this going in. I give two thumbs up to an inground pool!