What kind of things do you mean (in terms of what you like/least like)?
T2A was not my favorite era, but I like having the larger lands available. They're using T2A but excluding the Lost Lands for some reason. T2A was before pet slots were added, so you could do fun things like tame up a massive horde of bunnies. But no, that would be fun, so that's gone too. They're picking my least favorite era, but excluding what I liked most about it.
I liked gardening. This server doesn't have it. I liked custom houses. This server doesn't have them. I liked stealth, but they've opted to have stealth display step counts rather than auto-activate when stealth range is reached. And given that choice, I imagine that stealth is not off the global skill cooldown which means it's pretty much worthless because you can only take half a dozen steps every 10 seconds or so. I liked ninjutsu from later expansion for the smoke bombs for the aggro drop, they're not on the server. I liked alchemy, but they've nerfed explosion potions and there's no potion effect bonus from the skill so there's absolutely no reason to have alchemy on a main. I liked poisoning, but on this server you can heal through it. Hythloth was my favorite dungeon, and they've made it impossible to recall to the island, which means that only people who build a house there probably within the first two days of going live will be able to go without it being an incredible hassle. I preferred tailoring to blacksmithing, but none of the non-plain leather types appear on this server, whereas the metal types do. No skill bonus from alchemy, no damage bonus from lumberjacking, no spell damage from inscription, no anatomy+eval defense, no melee interruption from fast weapons, none of the later expansion skills at all, so there are probably only about 2 viable cookie-cutter builds total.
Champion spawns are apparently in. So that's good, I guess. Treasure maps are in, so that's nice if you want to have a fishing alt. Runebooks (thankfully) are in too, so that makes it not completely miserable to travel. So yes, there are a couple choices they've made I like. I don't particularly miss that they're not adding in the late expansion artifact grind routine. But overall it seems like An Corp's specific target audience is people who want to play halbard-mages for the sole purpose of complaining about halbard-mages. They've gone to incredible lengths to insure that it's the only competitive playstyle. And along the way they're omitting a lot of quality of life stuff for no obvious reason. When I played before the revamp, they'd removed the ability to say recsu and recdu to activate level teleporters, they'd nerfed resale value of books, they were using the antique "show no information" version of item info, mounts are gone...why? Just...
why? And meanwhile they're going out of their way to add features that don't interest me at all. Like...more boat variety. Apparently there are 8 different craftable boat types for carpenters. Why was that a priority?