It's not just the server issues, it's that the app logic is terrible. When you hit a Pokemon with your Pokeball, if there is a network error, the app just freezes. The ball drifts to the ground without blinking, and the loading indicator appears periodically, but it never progresses past that point. It just flat out cannot recover from dropping packets, no matter how long you wait. And it's not like the network is down; if you kill the app and reopen it, it is able to load the information it needs.

In many places, this happens with at least 50% probability on a mobile connection. It literally fails more often than not. The advice people are giving is to turn off LTE, which seems to help for some reason. But come on.

Have to kill and relaunch the app, and the app launches really slowly. it feels like the initial loading bar is also reliant of their servers, as I've had it take upwards of 30 seconds, or a few times even hang indefinitely.

Once you get in it'll still have to download locations of nearby pokestops and gyms, which is another chance to hang and require a relaunch. Network glitches are not handled gracefully.

On the hang while catching a Pokemon: my guess is it's trying to ask the server if the Pokemon breaks free of the ball. Sometimes when you exit and relaunch you'll have gotten the Pokemon, other times it's totally gone. When the game works properly you get to keep trying, but if it locked up on network issues and made you quit, you don't get the chance. People are understandably annoyed at server issues screwing them out of rare captures.

Yep, the hitting-with-Pokeball into a freeze is by FAR the most frustrating thing ever. But at least you successfully catch a decent amount of the time >.>