Dan, its a bit different for myself as I shoot a P65+ so the sensors and IQ of the new IQ/Credo's backs are basically the same but at this moment in time I personally would have a hard time justifying investing a large lump of money into an IQ or Credo when considering the leaps and bounds CMOS technology has jumped in the new Nikon.
I don't know if its possible for MF companies to adopts CMOS yet but it has to happen at some point as the advantages of CCD are getting smaller and smaller, year on year.
I love my P65+ on the Arca and wouldn't swap it for any 35mm system but upgrading for funky features alone on the IQ's/Credos is just not worth it IMO. Obviously for you, the upgrade in IQ from the Aptus to an IQ140/160 would be quite different image quality wise but if your clients love your work and its just for the toys I'd be tempted to wait and see what develops in MF land. I personally think HB are up to something and wouldn't be surprise if they are first to the finish post with new MF chip technology.
I don't know if its possible for MF companies to adopts CMOS yet but it has to happen at some point as the advantages of CCD are getting smaller and smaller, year on year.
I love my P65+ on the Arca and wouldn't swap it for any 35mm system but upgrading for funky features alone on the IQ's/Credos is just not worth it IMO. Obviously for you, the upgrade in IQ from the Aptus to an IQ140/160 would be quite different image quality wise but if your clients love your work and its just for the toys I'd be tempted to wait and see what develops in MF land. I personally think HB are up to something and wouldn't be surprise if they are first to the finish post with new MF chip technology.