I am putting DCC into a Proto 2000, E6A & E6B. A unit powered with an ESU 58429, 21 pin decoder with a Nix mini board, and a Scale Sound speaker. I have also purchased an ESU keep-alive along with new Walthers Proto geared axles just in case the axles are cracked. I am installing an ESU 58210 sound only decoder in the unpowered E6B unit. The Proto units are still in the factory wrap so won't know about axles until I test run the unit. This project has been sitting for over a month. I need to get this done.
I prefer ESU for diesels and TCS for steam locos. However, I just bought an Athearn Genesis UP, 4-8-4 at the train show last weekend and it has the older MRC sound unit in it. I will probably replace the decoder in the FEF with an ESU because ESU has sound files from the UP, FEF, 844 loco that no one else offers.
In my opinion, the ESU sound files are far superior to the Digitrax but each to their own. The best speaker won't make a mediocre sound file sound any better.
My best to all.........John