Having purchased the ago processor, i had no doubt that it would perform well with 35mm and 120, however it was also the possibilty of doing 4x5 processing that has turned the ago in to the most significant piece of equipment i have bought in years. The 4x5 holder works in a similiar way to the older “20th century reel” which i once owned. Its easy to load, and in conjuction with the processor makes developing 4x5 easy!. It provides even development, no strange marks etcand all the other benefits that gonalong with the ago. i have tried a number of the 4x5 developing products i.e mod54, 20th century and mosr recently the stearman press. The best previously was the stearman, but that was also not without its issues. This product is excellent, highly recommmended !