I haven't checked on this site for a while - so sorry about the delay in responding.
The Bessa III/667 finder is similar to a Bessa R3A/ZM finder. Very bright, clearly defined frame lines (verticals shift as you change from 6x6 to 6x7). Plenty of surround too - you can see what is happening outside the selected frames. The rangefinder patch is clearly defined and bright.
As with the Zeiss/Bessa it does require that you have your eye centered in the finder - otherwise it is not clearly visible. Part of this is inherent in the design to keep the finder bright and part of it is to ensure that what you see is what you get.
It is undoubtedly the best finder I have seen in any folder, inluding Plaubels.
I have been stocking up on 120 film for it. Dont know when it will arrive - but the Japanese Fuji dealers obviously have preference - oh well.