So every review for Thunderbolts has been extremely positive and insists you see it in theatres.
And you can search up the mid and post credits scenes if you want spoilers.
The “mid” one just a gag, the “post” one is the longest one yet at 2 minutes and 54 seconds (not counting Steve Rogers: The Musical in Hawkeye), and it is a set-up for Doomsday.