I have some experience with it. Game Rewind is actually gone. Starting this year, it's GamePass, and there's only one price: $100. So if you are really only interested in watching Panthers games, it may not be worth it. To justify the price increase, they added radio feeds to the package, which had been a separate thing in the past, and also put a bunch of episodes of Hard Knocks, A Football Life, Sound FX, America's Game, and lots of Super Bowls - even older ones. They have Super Bowls III, VII, and XIII for example.
The morning after games, there are condensed games available, so if you don't want to spend 2 hours watching the full broadcast tape, that's really nice. FYI, the full broadcasts do have commercials, but it's limited to just the first 10 seconds or so of the first one from each commercial break, and there's a button that lets you skip 10 seconds ahead, so you can effectively skip commercials). One of my favorite features are the condensed games. They let you relive moments of Panthers glory as they happened, and it only takes about 30 minutes to watch them all the way through. I also like the All-22 coaches film option (this feature is not available for preseason games). If you know something about football, it's a good way to make your own judgments about certain players, or what happened on a given play. I don't know when coaches film becomes available after games, but it's probably around the same time as the condensed games. Another cool thing is that you can jump around between specific plays when you're watching the full broadcast or the all-22 film. You can watch a play from the middle of the first quarter, and then 2 seconds later be watching a play from the beginning of the 4th. Etc. As for your other questions, only the all-22 coaches film and public broadcast camera angles are available.
The main drawback is that it's mainly an on-demand service, and it's not available at all while there are any sort of regular season games on TV. So you can't watch a 1 PM Panthers game while the 4 PM games are on, or during SNF or MNF. I think that covers everything important. Hope that helps.