If you want professional done dlc, stick with the ones RS sells. Although, some trackers here are very close to pro quality.
I went through the process of creating a couple of songs but haven't released them yet since I am still working on fine tuning.. Let me tell you, it is not as easy as load the score, load the mp3, export, done. There is a lot of adjusting and a lot of processing involved.
Some songs are done better than others, but I am not complaining, since I found a lot of songs on here that may never get released on RS.
Edit: I just have to add that I just recently got into the CDLC world. Prior to that I started with RS, the original, way back when it came out, on my x360. I upgraded to xOne, then got 2014, then Remastered. I bought it again for PC in order to be able to download CDLC's. I must say, RS is way more responsive on the PC compared to the xOne!