I haven't used 5.1 systems from Edifier but I do have Bookshelves from them. One of them, the Edifier S1000DB I use in one of my stereo setups which is strictly for listening to music and is connected Optically to an Asus Xonar DX. The S1000DB sounds excellent but then again it's in a different price bracket and also a 2.0 system which I have always felt is more tuned towards music.
The R1700BT I have is connected to my PC (motherboard's sound output) and also sounds lovely. What I particularly like about Edifier speakers is that they don't sound boomy like Logitech speakers. Even when you increase the volume with a substantial amount of bass infusion the sound signature doesn't get bloated and the vocals don't get drowned out. They sound clean with nice separation. I usually have my Treble & Bass knobs set at a flat zero except on the S1000DB where I increase the Treble and Bass knobs turned up a little. These are such clean sounding powered speakers and playing my music collection through JRiver MC on these has been very satisfying. I do sometimes tinker with the EQ settings under DSP & Output format.
One thing though, the remote control build quality on the lower priced speakers from Edifier aren't exactly great. They are just well, plain plastick-y and kind of feel a little cheap. The remote I received with the S1000DB though is nicely made and feels much more premium. The one of the R1700BT is the one that feels tacky. It does get the job done though and all the buttons on it work as they should. Edifier speakers are usually well made, finished and you generally won't go wrong with them. Good luck!