Ya shoulda let me know you were coming, a couple of weeks ago we had the power boat regatta, floating band barge, cookout, beer games, etc. Lake Ontario IS fun if ya go down the coast line a bit. 4 mile creek area, Porter On The Lake, Wilson harbor. All good places to hang out. Ain't those currents fun by Lewiston? You described them perfectly, feels like someone else steering the boat.
While your correct that the upper Niagara is a bit more exciting, I find it too packed with weekend warriors with the ol' "Hold my beer and watch this!" mentality. The lower river is definitely a bit more laid back, most peeps just cruise around or float with the current. If ya ever decide to come back, give a shout, first beers on me.
Oh, lower river tip, launch at Youngstown, we don't charge $8 bucks like Lewiston does