Summer 18u and 17u are very heavily scouted. I'm told scouting is increasing at the lower levels, but for the most part you go to those just to play and maybe build your Perfect Game dossiere.
All levels of programs scout. They're all looking for the best talent they can land, but it goes WAY deeper than just a few elite players. I took a 17u team with only 13 players to East Cobb in 2007. It was truly a pickup team put together for just that one week, to take some kids I thought could use the help down there to be seen. 11 ended up recruited by Division I teams and another by a highly regarded Division III team. Not all of that was a result of the one week in GA, but in several cases it jump started things for them, and in at least one case a pitcher went from discovered to committed in about 2 weeks.
In the fall, the 17u (players who were 16u over the summer) is picking up more attendance but I think it is often in a restricted recruiting period, so it's mostly for the sake of playing and PG's files. The 18u is the most heavily scouted event in all of amateur baseball and on top of that, is one of the top baseball experiences available to any high school player.