My use for slow 135 films changed when I acquired a 6x6 camera. When I had only 35mm, slow fine-grain films were of intense interest, but this faded as soon as 6x6 became an alternative. If I have enough light to use a slow film in a 35mm camera, then I have enough light to use Tri-X in a 6x6 and get better results no matter how the 135 is developed. I therefore shoot nothing but TX or HP5+ in 135; I consider 35mm to be for handheld work. In a 6x6 or 6x9 on a tripod, FP4+, because why not.