I have had this idea that is best to use the largerst format you can use in any application. Most of this year I have been able to use 4x5 or 8x10 and that sets the standard for sharpness, detail and smoothness of tonality for my prints. Last night I spent some time making 11x14 prints from a few trips I took where I had to settle for 35mm or 645 format. The 35mm was using techpan in TD3 and the 645 was using FP4 in Pyrocat. I also did some portraits in 6x6 with TRI-X in pyrocat.
You see I have this theory that with techpan, I can get MF performance out of a 35mm. Which in the prints is almost true. Certainly the grain from an 11x14 print from a techpan 35mm neg compares in smoothness with the 645 format prints using FP4 but there is a cost - sharpness - the 35mm techpan will give the smoothness and tonality but not the sharpness of the larger formats. Then the MF prints done from FP4 and Tri-x - same smoothness as the 35mm techpan but with added sharpness. Still no where near what I am used to with the 4x5. I kept looking at the 11x14 prints made from these and thinking how vastly different they are from the 4x5 format 11x14 (or 16x20) enlargements. I am sure that in 8x10 I am golden on both roll film strategies. I made some very nice 16x20 prints from my vacation shots done in 6x6 but the success of those is the glass - my Bronica glass in 645 is nothing like the Zeiss glass of the Rollei when you enlarge the print greatly. All in all, I think I can be satified with 8x10 prints from 35mm techpan. (probably the only reason to do 35mm at all outside of color point and shoot stuff) On the 645, 11x14 prints from FP4 in pyrocat is nice - they would probably look better as 8x10 prints as well though.
Bottom line - the 4x5 is not so heavy and setup is not so much longer and the satisfaction in the prints is an order of magnitude nicer when the print is on the wall. I think I am still searching for a better mousetrap for smaller roll film cameras though.