I currently have a 55mm/C 80mm/N and 150mm/C.
Coming from a Zeiss background where everything is tack sharp, I'm disappointed especially the 55mm. The "N" series has slightly better contrast than their "C" series, so I would definitely recommend those. For lenses, just get the best you can afford.
Since it's eaten up 5 inserts, (and waiting for another), it's a useless blob in the case on the floor. While the Rolleiflex TLRs just keep going & going.