This is not a 5-star device, but I'm willing to promote it from a 4 to a 5 because it solves a problem at a reasonable price that no other unit solves. I use this to play tunes in my car. I used to own a Fiio X1, but this unit is better for a car player. I'll explain. First, the AGPtEK A20 has a long battery life--long enough for me to run off battery in my car and recharge it occasionally. That saves me the hassle of having a power cord while I'm driving. That's a real hassle since I have to get a splitter to run my Garmin GPS and my player (and the GPS takes longer to boot up in this mode because it thinks its attached to a PC).
Other good thinks about this unit is that it supports FLAC format and allows for a micro SD card. I've converted all my old CDs to FLAC format (MP3 distortion drives me insane), and I can fit the entire collection (not a big one, I know) onto 1 or 2 cards. I can even attach this unit to a PC and copy files to it--don't even have to take out the card. This A20 uses a micro USB port to charge, same size as my cellphone. It has a random play mode, which makes my wife happy.
Dislikes. Text is too small to read without glasses, wish there was a way to enlarge it for us poor baby boomers. Device is small, however, wording can only be so big, I know. It's a pain to wake this unit up, pause it and power it down. How I wish player makers had a "power slave" mode, where, if the unit is kept on, when power is applied/taken away, the unit powers up and down also. Another pain is that the power switch on the side is hard to activate. Another pain is that when the unit goes into play-standby mode, you can only wake it up with the power switch. Still, I'll give this a 5 anyways.