I worry they added too much, making the game more complex with longer turns and more decisions. Non-optional feats at 1st level, weapon masteries, sneak attack options, and so on. This was clearest to me when they described the rogue who now gets a free off-hand attack when using a dagger, more options on their bonus action, and choices about how to spend sneak attack dice. It’s a lot of extra stuff and I see no way it won’t make combat take longer. Having seen what long combat can do to the rest of the game in 4e, I’m not excited for that.
It’s not clear to me if weapon masteries are limited to once per turn – I don’t think they are – and that seems like a problem after they said that it was a problem with stunning strike and divine smite. The idea of a fighter trying to knock a boss prone four to six times in a turn doesn’t excite me as a DM, that’s for sure.
Twice now WOTC made remarks on D&D Beyond and on their YouTube videos like “frustrating for DMs” and “monsters will hate this” and avoiding “mother may I” (or, as I see it, GM agency over the situation) which makes me think they steered it towards a game where the DM is the adversary. I have no desire for a game like that. Again, they tried to do this in the 4e days and many DM, myself included, felt like we could go down stairs and play PlayStation while the players ran the monsters themselves. I’m not eager to return to that.
So we’ll see but, for me, it feels like a big bag of candy handed to players with no consideration to how DMs have to deal with it when all this new stuff hits the table and we have to build a fun game for everyone out of it.
None of these changes matter if DMs don’t want to run it.
I’m happy to have a lot of options though. I’m enjoying my Level Up Advanced 5e game right now and Tales of the Valiant looks great with many similar changes to D&D 2024 but more restraint (they have weapon masteries but they can only be used once per attack action). When WOtC puts out the 2024 rules into the 5.2 SRD other creators can build more new versions as well so we can fix it if we need. Houseruling is also an option but it feels like a failure if we have to house rule it right away.
Anyway, those are my thoughts.