My knowledge of 5e is definitely useful for some things but it also feels like a hindrance at times. I chose to make a character into the Battle Master subclass of Fighter. I misread quite a few of the maneuvers.
- Commander's Strike uses one of your attacks and a superiority die to allow an ally to immediately make an attack as an action. This is useful for getting extra attacks out of especially heavy hitters like rogues. In BG3 it lets them make an extra attack on their turn. And I think they don't get any extra damage from the superiority die.
- Maneuvering Attack uses a superiority die to allow an ally to use their reaction to move up to half their speed and not trigger opportunity attacks from the target of the attack. In BG3 it lets effectively lets them get a free disengage on their turn (so not just against your target). So it's a little better and a little worse.
These were two of my favorite abilities as a fighter and it helped encourage me to keep other players focused when it wasn't their turn. Also, we had a big group, so getting to do something small when it wasn't your turn helped with the boredom.
I'm not complaining, some of the changes are good and some are bad. All in all you can't really compare the two because one is a videogame and one is a tabletop game. A lot of the abilities have great QoL changes for videogames. Guidance lasting for a while is great. Many abilities that last a long time now just last until a rest. True Strike got a buff -- it's not necessarily great or anything but not pointless anymore. (True Strike did have some very small very niche uses but all in all it was mostly bad since it's better to just attack twice 99% of the time.)
It feels like some of the spells have descriptions slightly wrong but maybe I'm just confused. I'm enjoying the game. It's rough around the edges but I do like it.