I've not fished the lakes mentioned but fishing any lake w/ grass is waaaaaayyyyy better than no grass lakes. Ex - Joe Pool and Cedar Creek
OH Ivie would like a word(I think, I've only been there once and it wasn't recently. But I'm pretty sure there isn't much if any grass there).
My theory on these lakes is they don't have the forage base that some other lakes do. But that's mainly a guess and I don't have any data to support it, other than fishing a LBJ and Stillhouse and not really seeing much bait. I've never fished Canyon.
I bring up Ivie because Stillhouse would seem to be a pretty similar lake on paper. Relatively small. Deep clear water. Timber. Maybe if it fills up it'll start pumping out more bigguns the way Ivie did when it caught a lot of water.