Yeah, the netcode is suspiciously bad. It's way, way worse than any other game of a comparable caliber. It's not only desyncs (though that's the worst part) but also just constant mini-lags. It's particularly visible when doing something like throwing a lot of items into the stash or an inventory full of stuff into the sell window. It feels like playing some old NWN server hosted in a dude's basement on a regular PC with household internet: it's playable, but the lag is a constant presence and really tarnishes the experience.
I think PoE has some of the best ideas in gaming history. The game's founding concepts are up there amongst the best five I've ever seen. Unfortunately, it's buried under a lot of really weird, low-quality design. I love the passive skill tree, but needing to spend 75% of your points on life nodes takes away a lot of the potential. I love currency objects, but the good ones are so rare that the only way to really use them is to be a trading tycoon. I love the item system, but good loot is so rare that the game feels unrewarding to play after a bit of time as you stop finding upgrades so quickly and are forced into obsessive trade mode if you want to progress into the real endgame.
Some of those things are improving, but very slowly and after such a long time that I'm not sure it's because GGG see the problem so much as just their need to try different things as expansions add up. Meanwhile, they've completely failed to deliver on their promise - and on the game's potential - of customized leagues and a wide variety of playstyle options. This is the very game that could have provided a self-found league, a cutthroat league, a craftsman league etc., but they've completely neglected that aspect of the game and provide only the 4(now 3)-month leagues as an alternative to standard/hardcore, with races being too temporary and competitive for many.
This was going to be the game that supported all the playstyles that people had been wishing that the APRG genre supported. GGG advertised the very thing in the game's infancy. They clearly have the infrastructure for it, they've promised to do it in the past, and there's very obviously a demand for at least a self-found league and a cutthroat league. However, for some reason, they staunchly refuse to with their league system what they advertised in the past, and what players have been begging for ever since.