Its like this-
Compare a high quality precision 85cm dish with a crap cheap budget 1m dish and you'll prove their claim correct "it can out-perform a 1m". Although this wont mean you get more channels it may just mean you get 0.1% extra signal level.
To gain more signal you need larger surface area, ie a larger dish. To gain slight improvement with the size you want to use, you can use a brand that provides more quality, accuracy and precision.
The Fracarro Penta is a quality unit, so you are looking at 85cm perhaps being about equal with a mid-range unit like a Triax 88cm, or a junk~dented~floppy~budget~nonprecision 1m dish.
In simple, if you want higher gain then use a larger dish.
Hope that helps.
i've got a penta 85 dish i cant comment on the signal as i've never had a 1m dish or a triax! BUT as pinky says it is a good unit BUT the comparisons made were probably against shite dishes and most probably need to be compared against other quality dishes like the triax.