Updates have helped but I don't think they've changed anybody's minds towards the game
Whether you'd enjoy it or not really depends on what you're looking for and what you mean by musou itch. If the worth of a musou title is heavily dependent on the formula these types of games use, then DW9 is really not going to be for you. It's a departure in so many ways (from the combat to the progression system to the ways battles now play out) and what it offers in return isn't necessarily better than what came before.
The only things I'd recommend DW9 for are for the combat and arguably the story. On combat, I really am only referring to the combat system here; the new flow combat system is actually pretty fun to mess around with. Don't believe anyone making Renbu comparisons, the new combat is fun as hell especially when you start to play around with weapon speeds. The only issues with the combat system have nothing to do with the combat itself (like the stage design, or the issue of cloning), though the combat system could definitely be improved a lot to be even better than it is.
Arguably the other reason to play Dynasty Warriors 9 is for its story. While the presentation of the story is admittedly iffy here (90% of the story is shown through barely animated, RPG cutscenes) I do think the story itself is good. It's not as tight narrative experience as DW7 is, but if you like the general story / period you'll be pleased. There are periods that are playable that weren't before (like Cao Pi's reign from Wei's side), you get to see each Kingdom develop and introduce more characters over time and I think the open world, though squandered in terms of actual gameplay, actually really adds to the story. Like seeing Fan Castle in relation to all 3 Kingdoms, or seeing Chibi and the massive river separating Wu and Wei really does help you contextualize everything.
With all of this said, while I do think these are the best elements of DW9, both of these attributes still have a lot of room for improvement. DW9's story presentation really is awful and can be pretty off-putting if you don't care that much for the setting. The combat actually has nothing wrong with it (no glaring flaws like losing Renbu level while travelling from point A to point B), but the "stage design" and to a lesser extent, the clones, do drag down the experience.
This wasn't supposed to be such a long post but basically, don't go for it if you really want a specific type of game and gameplay. If you're more adventurous, or if you have an interest in 3K / DW's story, or if you have a looser definition of musou and don't mind fighting 100's of mooks regardless of the formula, or all of the above, I'd say go for it.
