It is a bit obvious, just look at the contracts the actors have for each movie, Sebastian Stan signed up for nine marvel movies, but we all know that does not mean anything.
I honestly thought thanos in gotg was good, it shows he is patient and waits, in the aftermath of the avengers he liked the challenge of humans coming at him and smiles, and in the gotg he was calm and that actually shows good leadership, he doesn't blow up at the slightest things that would have pissed off a regular bad guy, the voice is perfect for him, I understand all actors are having the same to go through motion capture for their character to match their voice but even then I know marvel are holding him back until he finally is able to show off his great might and power
The thing that bothers me is the fact that all the infinity stones have to come together at one point and you know what, I CAN'T WAIT FOR THE HOT TOYS VERSION OF THEM in the gauntlet