Everything is great at Sebago other than the beds. If you don't have back issues, you will. Highly recommend the cottages for extended stays.
My main complaint is the dumpster trash pickup times being pretty random, which only matters because it's EXTREMELY loud and they sometimes come as early as 7:30AM - which is still supposed to be within the area's quiet hours. Really not a great way to be woken up, by big metal lids slamming against their respective receptacles when being set down by the forklift garbage truck.
Worth mentioning that the beach is a bit tiny, and maybe the cabins could be cleaned more thoroughly between guests (I am not picking up the previous guests' trash...
I wish the other people coming here respected the place instead of throwing their trash everywhere. Really sucks to see people's garbage everywhere I look - outside the cabins, on the surrounding grounds and woods, and even deep into the park.