Something between 6-7/10. So not good, but not terrible. Just mediocre. I would def. say I'd place them below the average of the franchise.
On the positive side, I think the atmosphere is great, the gym challenge and championship tournament feel more important than ever in a major way. Which is - for me at least - the greatest virtue this gen has, since this does a lot of the heavy lifting in the overall experience. Dynamaxing is an actual good feature and breeding pokemons to get your "Ideal" team is as accesible as its ever been. TRs are also a good feature IMO. And the Wild Area - while I do have some nitpicks on it - Its another overall great addition I hope they replicate in a bigger scale for future games.
On the negative side, really horrible graphics for "the first home console hd pokemon game", way too many interactions with supporting characters that add zero depth to story or progress - which already is a very weak story to begin with - Team Yell should not have been part of the game at all and the game wouldve kept the same quality IMO, they add nothing. The final "antagonist" of the game feels rushed and unnecesary, which I guess adds to the negatives of the story. 400 pokemons is way too little for today's expectations/metagame and it screwed up the competitive game - specially because they chose to leave behind many popular choices, but I guess this wont matter if you are casual fan. And I'd agree that the Post-game is really limited - not to say bad - But I do think most games have a really mediocre post-game so all in all is what I expected
There are other thing I could nitpick like not being able to turn off the exp share or very few trainers to fight againts (which I guess is the reasoning behind the exp share thing) but those are thing you end up getting used to, so all in all not that great of a pokemon gen, but def. no the worst experience I've had this year.
Either way this is a very divisive franchise so if you have played the previous ones you should give it a go just to judge for yourself.