What I know about brush development I learned from Jorge. It entails developing one sheet of film at a time which with 8X10 and 12X20 for me is not a problem. The advantages are far less damaged sheets of film...as in none. Additionally the film is developed far more evenly then tray development. The single sheet of film is placed emulsion side up in the developer and the surface is " painted with the brush". The brush used is a Hake brush and I continually "paint" the sheet back and forth and then I switch the direction by 90 degrees on the next pass. I find that the densities and times are very comparable to the Jobo times published by Clay Harmon and Sandy King. I believe that the times are probably somewhat shorter then conventional "interleaving" tray development.