There has been snow on the ice on all those lakes this year, so I suspect they are getting into a little dissolved oxygen problem. I didn't take my 02 meter last weekend. North Delaney was fairly slow - I only had about a dozen hits from 6:30 to noon, all but one from smallish rainbows. Only saw two browns the whole time, but probably 30 rainbows.
Then we moved over to the South lake and it was pretty hot all afternoon. My partrner and I were getting a hit every 5-10 minutes, sometimes faster, and almost every fish we saw hit. We pulled it away from everything that we didn't think would be at least an hour prize fish, but the action was very fast.
All those lakes are temperamental, though, Lake John included. Especially so as the oxygen drops and the fish move up higher in the water column to get more oxygen. They can be downright lethargic.