It goes without saying that Valve's upcoming Steam controller is a bit unusual - alright, it's very unusual. Aesthetically, it looks ridiculous. Functionality-wise... it has potential. It's going to be a hard sell, and Valve knows it, so it appears to be doing all it can to pre-sell us on it. Kicking things off, it's produced a quick demonstration video to give us an idea of how the gamepad works.
In the video, a couple of shooter games (including Portal 2) are played through, as is a game called Papers, Please and finally, the turn-based strategy Civilization V. While a game like Portal 2 already supports a gamepad natively, the standard keyboard + mouse control scheme was active here, showing you how well the conversion can be made, all the while the game is oblivious to the trickery going on.
Each game will utilize the gamepad a little differently, based on the profiles you're using, but the idea is that if the game in question can be played with a keyboard and mouse, then it can be played quite easily with this controller. A game like Civilization V can be played entirely with a mouse - no keyboard at all - so it's quite an interesting test for a gamepad like this. In the video, the gamer has no trouble selecting different options and moving around the map.
For the most part, these demos are quite good, but I admit that I'd like to see a little more - especially examples where scenes in games are rather hectic. In the Counter-Strike: Global Offensive example, there's no real enemies to fire at. In Portal 2, there are no precision jumps being made. In Civilization V, it's a turn-based game so there is no quick movement that needs to be made.
While the gamepad in Civilization V seemed efficient enough, I could tell just how much slower things were because of the lack of a real keyboard and mouse. In the video, going to a special section requires you to move your cursor up to the top and then scroll down a list. By contrast, you'd simply be able to hit an F key on a keyboard or surf through that menu quicker with a real mouse.
Of course, these are still early days, but so far I'm not left entirely impressed. I am holding out for something that will convince me that this gamepad is a winner, but that will probably require actually using it for a little while. I am willing to bet it will be the same for a lot of people.