I don't mind if it's Tony Stark, I just REALLY don't want him to be the quip machine he was originally. I really want to see RDJ play him with the same intensity he played his Oppenheimer character with.
Re: Russo Brothers, I'm way more Meh on them than most people. Infinity War and Winter Soldier are great, but even Endgame I struggle to get into on rewatches because so much of the run time is just spoon fed fan service. Then you look at the mid action movies they've done post Endgame and I really view them as the "safe" choice, but definitely not the most exciting one.