Our family (2adults, 2 teenagers) spent 2 weeks at Oneida lake. One week was still working remotely while kids enjoyed the shallow water to play water games or go kajaking or ride the bicycle in the neighborhood. The location is great, a little outside the Sylvan beach centre (off the crowds) but still easy accessible. We mostly cooked at home - easy with the well equipped kitchen and grill outside, and got some wonderful pies at Eddies!
The movable picnic table outside was our breakfast, lunch and dinner spot, always moving either into shade or sun, depending the time of the day. Also relaxed with a book on the lawn chairs, or enjoyed some badminton on the lawn. The inside is comfortable as well with all the recliners - and the screened in porch was very helpful at night. As others mentionned, there is no AC but if closing windows and shades/ curtains early in the morning it can be managed. One thing to mention which could be disturbing to some, route 13 is relatively close and the traffic is noticable, especially with open windows in summer.
We actually all brought our instruments to practice (guitar, flute, saxophone) and it was a great thing to have a piano on top of it to play,
All in all a great time, wonderful sunsets and beautiful area to explore around Oneida lake (according to my husband also great for back country bicycle rides) - oh and did I mention Erie canal and green lakes hiking/swimming?