My sister's Champion toilet is having a flushing problem. American Standard sent her parts including a replacement for the "flush tower". It's call the Accelerator Flush Valve, and I hope it cures her problem. The new valve is similar to a flapper, except that it pulls straight up instead of being hinged. They also sent her a new tank gasket and a special plastic wrench.
The AS website now touts the Accelerator Flush Valve, and the old flush tower is gone.