Playing Enemy Within again makes me realize how shitty some of the enemy mechanics were that are greatly improved upon in XCOM 2

Let's take one of the more frustrating things: Enemies that haven't been revealed by FOW going into overwatch and one of your troops triggering it from somewhere off screen.

Flying enemies. Difficult to hit consistently and they easily flank you and there's nothing you can do about it, because they can fly over terrain. Seekers that you hadn't discovered yet being invisible for 5 turns and suddenly turning up out of nowhere to incapacitate one of your units. Cyberdiscs are almost always accompanied by 5 or 6 drones, so you have to take at least one turn or two focusing your efforts on destroying them, or with some insane amount of luck hope you can take out the cyberdisc in one turn

UFOs: Incredibly annoying to deal with, because it takes so long to have the necessary firepower and equipment to take down anything bigger than a medium sized ship, so they just take free shots at allied territories or you hope they land and don't cause the panic meter to go up

This one is more of a personal opinion than anything, but chryssalids being able to one hit you and turn your units into zombies the first time you ever encounter them seems unnecessarily unfair. I get that the game is supposed to be hard, I get that it's supposed to feel unfair, but I feel incredibly unprepared by the time I first encounter them

Editing this post to clarify that these are also Long War complaints