Both American and Delta have invested heavily in truly usable internet, which distinguishes them both from United whose internet rarely works when I fly them.
American says they are now 95% done with their project to install satellite wifi in their aircraft, and that they will complete the project by May. What that means is that if you’re flying an Airbus narrowbody (A319/A320/A321) or a Boeing 737 you should have fast internet on board.