there is so much of variability even in the same machine in fields checked during different times of the day,or when patient is tired etc that to compare fields of 2 different machines does not make sense.
The Flicker-defined Form perimetry is much more sensitive to early glaucomatous changes than SAP (w/w). It has however, a much smaller dynamic range, i.e. if relative scotoma are present in SAP there will already by absolute scotoma on Edge-Perimetry