Medium format lenses are slower, and slower to peak, than 35mm lenses, so
f11 may be the best aperture, with the center at f8 a good reference.
The memory dims, but I THINK I remember that the 80mm f2.8 was decent
all over at f2.8, nice by f5.6; the 55mm cleaned up over most of the frame by f5.6; and the 150mm f4 was pretty decent over most of the frame at f4 -
but this is almost guessing at this point (I remember thinking that they were good lenses, up there with the overrated Zeiss lenses for Hasselblad -
in other words very good considering the film area, but not up to the
best for 35mm on a unit film area basis [in yet other words, larger format
buys you better tone/grain characteristics for a given print size, with
a bit extra detail potential, but it is not directly proportional to the film size increase {and using it is a pain, compared with 35mm - though sometimes worth it}]).