You can get an idea of the FreeWrite "experience" by trying their online Sprinter app.
https://sprinter.getfreewrite.com/
It would drive me nuts not to be able to correct typos I discovered a few lines up, but I understand the basic principle. You're supposed to just pour out the words in a creative flow and produce what they sometimes call in screenwriting, a "vomit draft."
Something like Freedom wouldn't work for me on a device capable of getting online, because, when I'm writing on a computer I'm in the habit of doing research as I go — even looking up the meaning of a word can send me on a three hour "journey." I used to look up a words in my dad's 1913 Webster's Unabridged (India paper) dictionary and would still be leafing through it hours later — one definition leads to more definitions and then the origin of the word and "Oh, I didn't know that... what about...?"
That said, I would never be able to justify spending the kind of money it takes to buy a FreeWrite, especially since an Alphasmart Neo does the job AND allows you to edit that typo three lines up.