Shot with a 6003 for a long time. Agree with all the above - with a few adjustments. The batteries can be successfully rebuilt with newer cells, giving really long life. I used to shoot about 200 images on the original batteries, but with the new cells, the number of frames you can shoot is more.
The lenses are all pretty much still available. I'm partial to the Schneiders, but there are some Zeiss ones too, as well as some Rolleinars, which were more economical in-house made lenses. I don't think the AF's work on 6001.
Lots to like about this camera - very easy to use.