I personally prefer BAT myself, and have purchased some. I have also used the Brave browser, which is buggy, but not bad. And as the article states, BAT has a unique idea, which is what you want with any investment methinks. However, AdEx appears to have greater popularity... perhaps due to better marketing?
Read it here:
https://coinanalysis.io/bat-versus-adex/
So, which do you prefer an why?