Unless you play rts games or stuff that actually needs a mouse to use, I would say no. Its terrible for shooters, racing games, etc...

 

The controller is plug and play, but you generally have to adjust controls for just about every game you want to try mainly because the touchpad "analog" sticks are so touchy on their own. Steam does have the luxury of providing 3 different default profiles, one for xinput controls, one for "precision mouse" controls where the right pad is used as a mouse and the rest are used as controller buttons and then KB/M mode where you can map KB/M to the controller. You can also download profiles from other users who've adjusted controls themselves.

But if you already own various controllers, there's absolutely no reason to get one. I got one myself and, for the most part I don't use it unless I want to be lazy and play Factorio on a TV or something.

 

I bought one when it was half-price on Amazon. Some games don't like it at all, but most of them I can just download the most popular community input profile and be done with it. Honestly I can't imagine using any other controller - the games that don't play nice with it are games that need a real keyboard and mouse, anyways.

 

I was tempted to get one, but I can't convince myself what the benefit would be over the xbox 360 controller I have that I use for the occasional RPG I play on PC that are just horrid to play with kb+m.
Might just be me, but if you need to map keyboard keys to a controller, you may as well just use the keyboard.