A. Gullstrand recognized the fact that the Einstein field equations are applicable only to static systems and not dynamical systems. That is why Einstein did not get the Nobel prize for TGR.
As early as 1917 experts in tensor calculus had found out about the flaws in TGR:
A paper by T. Levi-Civita in 1917, one of the inventors of Tensor Calculus, showing that Einstein's pseudo-tensor is nonsense because it leads to the requirement for a first-order, intrinsic, differential invariant, which, as is well known to the pure mathematicians, does not exist:
http://web.archive.org/web/20090902090420/http://www.sjcrothers.plasmaresources.com/Levi-Civita.pdfThat is why, in that same year (1917), H. Weyl extended TGR by using non-riemannian geometry:
http://www.jp-petit.org/papers/cosmo/1917-Weyl-en.pdfTGR is an incomplete, subluminal theory. What we need and want is a superluminal theory, which unifies electrodynamics with gravity.