Out of all of these you mention Distrokid is the best for a number of reasons. I have used CD baby but they closed their online store down back in march of this year. Anyone that has CD's should check to make sure that CD Baby is still selling them. They are also going to get rid of their download cards. They will still honor the ones that are out there for now. They still make CD's and band merchandise and they still do music distribution. This caused a great deal of headaches for me.
First CD baby's website is hard to navigate and it is a bit confusing. I spent hours trying to update the music I had in their store only to discover that the music is no longer in their stores. The website still had the music and artwork listed, but said updates were needed. After getting a call from tech support I discovered that I had to re-upload my music because when they closed the store the took all the music out of their server even though it was listed as still being there. They don't really seem to know what they are doing. They seem to justify this by saying we sent out emails to everyone telling them what we are going to do. That much is probably true, But I deleted the email and never opened it because it probably came bundled with the endless advertisements they would send trying to get me to buy their custom merchandise and upgrade my music distribution. So anyone who still has a CD baby Account needs to check to make sure their music is still there. If your music or CD was only on CD baby it is probably no longer available.
After doing some online reading I discovered that the founders of CD baby and Tunecore are no longer with the company. This is according to a few articles I read. In those articles both founders of those companies recommended Distrokid. I created an account with Distrokid and the difference was huge. First CD baby charges per album or song on it's distribution service. I think it's about 30 bucks a year per album for the basic service and $79.00 for the Delux distribution. Distrokid charges about 20 bucks a year and that is for all your music and full distribution. You can upload as much music as you want and it's unlimited. They get your music everywhere. My music is on Amazon, iTunes, Apple Music, Google Play, iHeart Radio, YouTube, Spotify, and the list goes on. You can even choose which venues you want your music to be available. Distrokid offers 3 account types. I went with a 35.00 a year account because it allows me to upload music from one more artist. You can even upload cover songs and split the commission among artist who wrote the song you recorded. The 79 dollar per year account on Distrokid makes you a record label and you can upload music from many independent artist.
So all you really need is the Basic account. The cool thing about all this is Distrokid registers your music with YouTube. If anyone uses your music in a YouTube video Distrokid will get YouTube to put ads on that video and you get the ad revenue for it. This is a great way to monetize your videos if you have not yet reached the stats required for video monetization. Instead of getting paid from YouTube you are getting paid from Distrokid. All you got to do is put about 5 seconds of one of your songs in the video. You can even do it at the end if you want.