Bah. I know how to use a meter fine. I use a spot meter quite successfully with my view camera. But I do think C41 looks slightly better with generous exposure - less apparent grain, gobs of shadow detail. You're right that it looks fine at 400, and not too bad up to 800. But I think anything from 200-400 is reasonable and 250 or 320 is a slight improvement, especially for someone who isn't really comfortable using a meter and just let's the camera decide. C41 does have a lot of latitude. When in doubt, give a bit more.