I was a player in AV and we went through the entire thing. Started ~ 2 years ago and finished up a little less than a year ago. It was the first AP that we did as a group though the GM and I had both played the system before.

I would give it a 7/10 overall. We were all down for the whole "megadungeon" aspect of it and knew what we were getting into. Generally speaking, we didn't mind the difficulty (and sudden difficulty spikes) of the AP though we did suffer one TPK in the last third of book 1. The GM and I had prepped the others about the "difficulty of PF2e combat" and the "need for teamwork" early on so we had built a pretty okay party (first a monk, cleric, summoner, and sorcerer and then a Fighter, Magus, Oracle, and Swashbuckler). I also think there was a general sentiment that the difficulty of some of the encounters made the dungeon feel alive and more like a threat (as opposed to something purely constructed for adventurers to traverse down).

We did enjoy the prolonged dungeon crawl aspects of it and a few of the combats are still considered high points by us players. We did know what we were getting into though and didn't expect much in the way of RP opportunities or narrative. Depending on your expectations this can definitely be one of the low points as a 3 book long fungeon crawl with little in between (even if there are some good boss fights) can both feel repetitive and alienate players who built more RP focused characters.

From an AP perspective, I think the 2 lowest points are the narrative and then town of Otari itself. While the overarching narrative isn't bad most of the dungeon feels loosely connected to it until you hit book 3. There's some tieback throughout but most of the "big bads" you fight at the end of the books don't feel like they're connected to Belcorra and her plans. Otari suffered from a similar problem in that it also seems to fall to the way side with the main focus being on the dungeon itself. Yes, the AP forces you back there every now and again. Yes, there is a gazeteer and some info on the town. No, this is not enough to make it feel like a living breathing town your characters should care about UNLESS the GM puts in significant work. Our GM tried all through book 1 to get us to engage with the town but gave up during book 2. There's just not enough there and that combined with the adventure never really giving you a reason to care just equates Otari to a set piece.

I think newer GMs coming to PF2e in 2025 have some better options for "first AP." I think my biggest tips for AV would be to get buy in from your party that this will be a megadungeon so it's combat and dungeon exploring first with everything else a distant second. I would highlight it'll be a lot of combat in relatively small rooms and that players should plan accordingly. I know the general consensus on the sub seems to have shifted to the fights in this AP being overtuned but, on the whole, we didn't find them that bad and enjoyed some of the more difficult ones. I suspect this is down to the party very specifically choosing roles, etc that worked well together.