The Steam Controller is an interesting gamepad at the very least. Here's my updated opinion on the controller after spending a further half a year with the device.
When I reviewed the Steam Controller back in August last year, I praised it for being well-built and something different. A downside to the product, however, was that is was indeed different from other controllers. This caused me to relearn everything I had already discovered in using gamepads, including the infamous Duke for the original Xbox. It's an odd feeling to move from any modern controller to Steam's offering and I believe that to be an obvious part of the reason why many avoid it.
Another two main points I raised were the lack of a second joystick and being forced to run Steam in Big Picture mode to change out configurations and other tasks. Do I still stand by these? Not entirely. I miss the second joystick, but not as much as I did when first wielding the Steam Controller and now find it much easier to use without actually thinking about it. As for the latter point, I'm no longer firing myself into Big Picture mode to change a few settings because I take the time to get everything set before launching a title.
I gave the Steam Controller a solid month of use before writing up my original piece on the gamepad, but I'd say it absolutely can take even longer to get used to the unique layout and functionality. I was fairly capable at the time in a number of titles, but it wasn't until I deployed the Steam Controller in Star Citizen did I finally get used to it without spending a second to think about what I'm going to do physically to carry out a specific action in-game.
This is the PC gamepad you've been looking for... sort of.
I'm now at seven months and substantially more time using the gamepad, and that's led a layer of dust on my Xbox One controllers. Whether it be Cities: Skylines, Star Citizen, GTA V or even Rocket League I'm picking up the Steam Controller and performing well enough in-game that I doubt I'd be able to extract much more from available skill if I had one of my other gamepads in my hands. The haptic feedback is still amazing.
The only issue I have, which incidentally only appeared as I became even more familiar with the controller, is with the two rear paddles. I seem to have a habit in accidentally pressing them and causing mayhem on-screen. Other than that, I'm a happy bunny in a loving relationship with Steam's gamepad. In fact, it's reached the point where I want to get the Steam Controller out if I'm having a session on a console — and that's a testimony to how good this thing can be.
Oh, and the four main buttons still feel as though they are in the wrong place, but that may just be me.
So do I recommend the Steam Controller? That's a tough question. I think you absolutely should if it's on sale as it's an interesting and unique experience. That said, take note that it takes some serious time investment to get used to the layout and how everything works. As for me, I enjoy using the controller and can see myself continuing to do so until version 2 gets released or something new, different or better comes along.