I have the SJS versions on my daily and use in friction mode. Right shifter is a joy but left can be a little awkward with the amount of throw. They also mount using the bolt from the shifter unlike the Pauls. I can post a pic of my setup if you like?
My son bought the bike off fleabay with all the Paul stuff fitted, he really likes the thumb shifters, I’ve ridden it and personally I prefer a decent set of MTB trigger shifters, but that’s just my personal preference.