I haven't used all of these products. I have used several generations of Teensy for projects. I'm a big fan! They're powerful, well thought out, and inexpensive

I haven't used all of these products. I have used several generations of Teensy for projects. I'm a big fan! They're powerful, well thought out, and inexpensive. Paul Stoffregen (creator of the Teensy products), is amazingly responsive to users. The only downsides (for some) is that you have to know C to program them. You can use the Arduino libraries if you want, which provides you with a lot of functionality with very little effort. If you have a specific project you'll be manufacturing, you won't want to use something like this. You'll want to design your own board that only has what you need. But for prototypes, small run, or one-off projects, it's hard to beat the power of a Teensy 4.