I disagree on it not feeling right for shooters. I've got mine set up so the right pad does large scale camera movements (when you pull a trigger your thumb moves, so it's no good for accurate sniping unless auto-aim's on) and then when I press one of the back paddles it switches to 'high accuracy mode' using the internal gyroscope for aiming. Think of it like a button to hold your breath while sniping for greater accuracy.

What I'd say is that the steam controller feels light (I want to add more weight) and its biggest strength is also its biggest weakness, customisation. You can almost guarantee that out of the box the control scheme won't feel right for you, and for most folk that's when they stop using it. If you put in a little time tweaking it though, or trying out the configurations of other users, you'll find it can be far more powerful than a standard xbox 360 controller. If you consider the whole PC vs console argument boils down to one's easier, one's more flexible, I'd even say the steam controller is the perfect controller for PCs.

I'm in a similar situation due to long term back problems and tbh I've found the best combo is a wireless xbox pad for games that need a controller and wireless keyboard and mouse for anything else.