I haven't played Arx since the original release, but I'm guessing it hasn't changed much. It did feel like the worst part of the game (I mean except the final fight, which was very tedious) and is pretty messed up: it seems like they really ran out of ideas and/or time. It's a shame, it has some potential to be really interesting, and while I'm not sure that an isometric game can capture the claustrophobic but kind of awe-inspiring feeling of Divinity 2's Aleroth with its narrow winding streets and tall buildings, it could've come close.
But it didn't. It felt empty, barren and dead. There was little to do, little to see and what was there seemed awkward, disjointed, incomplete (I mean there were so many instances of "placeholder" in the description of things) and perhaps for me the worst thing is that it seems to tear up a lot of established lore and reinvent it. I'm not sure for what end, or whether it was perhaps a new writing team and the pressure also affected how well-acquainted they were. Although it's not as bad, it's caused me to have a bit of a Mass Effect 3 moment and I guess I'm happy with OS2 until about the end of Act II. After that... well, I'm not sure how they can reconcile e.g. Divinity 2 in particular with OS2 and unless they can come up with some sort of Grand Unified Theory of Divinity one is doing to have to be classed as non-canon. And for me, it's OS2 that's the odd one out.
Perhaps the worst thing for me is something that's been a bit of an increasing problem all the way through OS2 which is that the Larian "vibe" seems to be quite diluted, but nowhere more so than Arx. The Divinity games have always had an interwoven thing where absurd humour and poignancy are delivered in equal measures, and while they were present in OS2 I think they were toned down too much, to the point where even simple little things like the handstand after climbing a ladder were deleted because people were saying it wasn't serious enough. But the games were never about taking themselves too seriously and if they do I think they run the risk of just being like any other game. If anything, I felt that Inquisition had more humour in it than OS2 and to some extent the Dragon Age franchise can be a little po-faced in comparison.
Although I've meandered about a bit, I guess my initial experience of Arx is that I have little desire to replay it unless I hear that it's changed significantly. And I'm not hearing it.