Well, maybe I'm being too resistant to change. I liked the prosthetic Thing in the previous movies because CGI
at the time was not up to portraying a basically human character as realistically, especially if you wanted that character to deliver dialogue and convey a subtle performance effectively. But in the wake of
Avatar and
Rise of the Planet of the Apes, I suppose that's no longer the case,
if the animation is done well enough.
And that's still the caveat with CGI to this day. Most people make this facile assumption that CGI can do anything more easily than conventional effects, but actually it's much harder to simulate real things convincingly in CG than with other methods, and it really only looks better if you have tons of time, money, and talent to put into it. Really good CG would be better than a rubber suit, but a rubber suit would be better than mediocre CG.