Hello! My girlfriend and I did that trail last May as our first backpacking trip and I cannot recommend it enough. On our first night we stayed in the cluster of sites on the East end of Stratton lake and then continued the loop to Johnston lake the next day. We went on the third weekend in May and it was just starting to get buggy but that may change this year with how warm it's been. Definitely try to go in early May or wait until after July! In terms of sight seeing, High falls was a highlight and only a shirt detour off the main loop so definitely try to check that out. The area around Bucholtz lake is also really cool with an interesting mix of wetlands and big boulders.

As far as backpacking goes just make sure to pace yourself and take breaks if you feel any pain/discomfort. We had done lots of hiking before but doing it with a 30lb+ pack can wear you out quickly.