It's sturdy and built really well. It feels like it will withstand a few drops. However, after using it for 5 months I found the following problems which make it annoying to use.
1) The touch buttons are very easy to accidentally touch without intending to. If they were physical buttons it would be better. There is a button-lock/hold slide button on the side which would be useful if there werent such a long lag between flicking the hold button and being able to use the device again. There is an annoying padlock animation that it must go through on the screen before allowing you to press the buttons again and it takes a couple of seconds.
2) It doesnt remember the last bluetooth device it was connected to. So if the machine is turned off and then on again you need to go back to bluetooth menu to connect to your headphones
3) While in the middle of a track pressing back doesnt go to the beginning of the track, it goes to previous track
4) There are slight delays when using the buttons. This is especially evident when playing/pausing.
5) Touch buttons dont always register a touch. You also must look at the device to see which one youre pressing, so you cant just put your hand in your pocket and feel your way to a button to press it.
6) Its only happened 3 or 4 times but sometimes button lights get stuck on and it needs a reboot. Dont know what causes it
7) If you leave the device on with the screen off it looks like the device is off. The batteries drain really quickly this way so you need to double-check to make sure you turned the device off and not just the screen. There is no auto-sleep delay.
All in all, I am most impressed with the build quality of this and the price. If you remember to turn it off properly the batteries can last a while. Putting real buttons would fix many of the issues I mentioned above. Some of the other issues can be fixed via software.
I wouldnt buy this again had I have the choice. The listed issues are just too annoying to look past.
November 2020 update: I left the device on a cushion seat and accidentally sat on it, this cracked the screen. This was between two soft surfaces (my butt and the cushion) and I was surprised to see the screen cracked. You could see the crack starts from the top-middle of the screen so I am assuming there is a fault with how the screen in mounted to allow it to crack to easily. The entire LCD screen is illegible now so the device is useless.