It's great. It has a simple design but it's iconic. Even though I know there's better flying types in Kanto, I still use it often just because I like how it looks the best. It's mega is cool too. My only nitpick is that it's basically just a bigger Pidgeotto but that's not a big problem.
It's amazing. The concept of an alien virus is just really cool, it looks great, and has a great battle theme. And in ORAS you even battle it in space which is awesome. One of the best mythical Pokémon.