Well, the speed of the propogation of gravity waves in GR was equal to the speed of light in a vacuum. That may be off the table now.
What bothers me about Einstein is not that he made calculation errors or had something grossly incorrect. It's that he, and pretty much everyone since him, have assumed that Minkowski space actually represents reality, instead of a very clever mathematical shortcut equivalent. It relates to A-theory vs B-theory of time and whatnot. Einstein basically eliminated the necessity of Lorentz's aether, but then still insisted that something is being "curved" by objects with mass. A bit confusing.