Product review (3 stars): Waste King Splash Guard and Sink Stopper
The replacement Splash Guard works well. The the 13 year-old one had lost flexibility, clogged, and needed to be trashed.  Not only did new one cut the "splashing" but also reduced some of the noise.

The Sink Stopper is utilitarian at best, doesn't seal particularly well and is better placed out of view when company come over.  This would be better in a slop sink than in the kitchen.  Ugly, but in the end, I got what I paid for.