Okay, first week impressions.
It's a terrible gamepad. Absolutely the worst I had ever tried, worse even than Logitech F310, and that one caused physical pain after 10 minutes of fighting with the triggers or a minute or so after trying to use the dpad. Bumpers are beyond terrible, face buttons are too close to each other, in a weird position and generally feel cheap, back paddles are very loud. Gyro controls are terribly imprecise with the two games I've tried (Need for Speed Hot Pursuit and Grid).
But it's a really neat wireless keyboard + mouse combo. I wouldn't play any of the gamepad games on it given a choice (and I have DS4 and will soon receive WiiUPro, so there's lot of choice), but visual novels? Point and click adventures? Mouse driven games? Bring it on. Touchpads are great, and as long as you map the mouse buttons to triggers (which are great!) instead of touchpad-click (which isn't, really), you're good to go.
BPM configuration options are amazing as well, especially the radial menus for quick access to keyboard shortcuts. But the whole interface is a mess, getting and comparing user configs is a mess, and the whole BPM mode has a tendency to crash now and then.
Overall... Not sure what to think of it. It's bad for things gamepads are made for, but amazing for things gamepads are terrible for...