CR does not give you that blast of levodopa many of us need to get well and truely "on".
Chasing an "ON" with extra sinemet is usually a bad idea, becuse you wind up over-dosing on sinemet. You know you have "OD"ed by headache or dyskinesia. Additional sinemet will throw off your subsequent doses too. It is better to find your theraputic dosing amount and schedule and adhere to that.

Charlie