Overall it's a pretty solid controller that I would get on sale, but probably wouldn't get for full price myself. The stretching feature is really cool for horizontal and vertical gaming on a phone, but there's wireless connection limitations and the trigger buttons do not have the gradual input. The triggers are fully on or off without being pressure sensitive. It meets my needs for most games, but there are some that I would rather use a different controller for.
I could only get the Bluetooth pairing to work with one mode (HID), and that mode doesn't have a home button for navigating Steam Big Picture. It reconnected next time without issue for wireless mode, but none of the other modes would connect. My phone could see them but would refuse to connect.
I preferred setting it to the x-input mode and plugging my phone in directly. That way Steam link sees the controller as an Xbox controller and the power button works as a home button. The instructions do say that the controller might not work with certain phones or games, so I guess that's why.
I was able to plug in my phone on the controller for wired mode without needing to take my phone out of the case, which was really nice. The USB c plug can be flipped up to use or down to be out of the way for wireless mode.
The stretching feature is nice. It's more portable to take the controller with you since it takes up less space when not being used.
The grips for the phone work well to keep the controller in place in wireless mode as well. I had to squeeze it together a little tighter from the shape of my phone case to get it settled in as snug as I could, but then it stayed nice and tight.
The shape of the controller in the hand isn't as comfortable as an Xbox controller to me, but it's not terrible. The texture on the back of the controller gives me good grip which I do like.