I will just write about the first three books together. The first is quite good and I recommend it among litrpgs it does stand out, the next two are still decent (honestly they are retroactively driving my impression of the first down). The MC is likeable and interesting enough, and I am fond of AI companions. Some good fight writing too imo, more so in the first book before she gets a bit too imba. And the books mostly know not to dwell on uninteresting parts. (Also not to over do it with printing every single ingame notification like some litrpgs do, there are still plenty though.)

Now as with many litrpgs it reminds me not so much of someone playing an MMO but of someone playing a table top version of an MMO with an DM/GM with severe monty haul tendencies. 90% of her game time is spent on one quest or another where she was the very first person to discover it and she gets loads of loot for it (and that is from the first levels the loot doesn't seem to have much scaling with levels just look what she got before even reaching level 10 that staff should not be handed to a new player), and it gets glaringly obvious when translated to real world money because the amount of real cash she makes in a month from a game is plain absurd who is exchanging all that cash for virtual currency?

And this series has the same problem other litrpgs going this route have, making her special has limits and if you do it the wrong way the rest of the gamers just seem to carry an idiot ball. Like in book three where she solves some time limited quest on her first try and is the first to succeed. Thing is the quest is well known and people can try several times, she did nothing that nobody would have tried over the time, yes the average gamer is not all that great at solving such things but the best ones are and can be supremely persistent. For that matter she gets many thing by talking with enemies and while many players wouldn't, you know there would be some playing diplomancer style in a setting where you can not only make bets with dungeon bosses but outright convince them to ally with you under the right circumstance. It suffers a bit from trying to make her special instead of just talented and determined.

But damn I would like to play the game.

Edit: Looked ahead a bit in book four (even if I won't read it properly at this time) what she gets in that book is just going too far you should have to plot specifically for something like that. That is the problem, she is a skilled fighter and smart so being successful is fine but getting as much as she does needs more justification to not feel like the world just hands her stuff, it needs long term planning instead of just somehow ending up there. And I am starting to like the MC less. I think it will be a while before I read book 4 probably, gotten tired of the series.