I have utilized both, in general I don’t like to work on reeds with the ATG sanding block if the reed is too wet. I do flatten the back of the reed with the reed geek or reed knife, whatever is handy. I like to do small adjustments in balancing the sides with the reed geek but if a reed is a harder one to begin with I do like using the atg to bring it down quickly , and balancing as per the ATG instructions works as well for me also. I also like to use microfiber polishing cloths for fine finishing of the reed as well as reed rush.