I'm looking at buying a 645Pro (mainly for the 80/1.9_. I found a few kits with winder and prism but there seem to be two prisms, the FK402 tube-like one and the more normal looking FE401. I found some tech specs that show the FE401 to have more metering modes but I'm not particularly interested in metering. My main question is this, for whoever has used both: is one easier to use than the other for MF? Brighter/clearer? Or are they the same and just differ on metering?