I bought my Difrnce MP1820BT as a replacement for an older model (the MP1805), which worked properly but, due to a rickety housing made of cheap plastic, was very difficult to handle and frequently fell apart.
Besides the fact that the MP1820BT is robust and attractive, I had two other requirements: Bluetooth and the micro-SD slot. In principle, the thing is recommended – certainly because of the favorable price/performance ratio – albeit with some less pleasant features.
The manual is brief, but the operation is so intuitive (also by touch) that you hardly need it.
A carrying clip would have been useful, but is not indispensable.
So far the battery life seems fine, with the annoying side effect that the MP1820BT does not turn itself off over time when music playback is stopped. Then you don't see anything that it is still on, so that the battery secretly runs out before you know it.
Besides playing music, the MP1820BT has some other tricks – displaying photos, movies and e-books, and you can use it as a dictaphone – which I don't use so I can't say anything about it (except I think you're on the first three have absolutely nothing, with that tiny screen).
FM radio unfortunately shines through its absence. Totally unforgivable is the lack of even the slightest form of equalizer.
The supplied wired headphones are less than average, but with good quality Bluetooth headphones (a JBL TUNE 110 BT in my case) you have beautifully clear sound with excellent bass reproduction.
Extremely annoying is that Bluetooth is turned off by default. When you switch on the MP1820BT, you have to click through everything for a long time to get your wireless headphones to work.
A curious software feature is that folders in the file viewer are not always displayed alphabetically. What you add afterwards is stupidly put at the bottom in the order it comes in. The only way to get your music collection neatly sorted alphabetically is to extract or format everything, put the micro SD card in your computer and copy everything back to it at once. (I don't know how the internal memory behaves in this regard, because I don't use it.)
Incidentally, this problem is structurally characteristic of Dfrnce: my aforementioned MP1805, now about six years old, already had it.
But still: all things considered, the Difrnce MP1820BT is a fairly good MP3 player, not least because the friendly price makes up for a lot.