Thanks. Apparently the IV is slower to focus. No problem with the warm view
The EDII was quite ground-breaking i thought; reasonable price for very good optics, a flat field, good very close to the edge of the FoV, excellent resolution and a fast but accurate focus. I'd had the original ED beforehand and the reduction in CA in the EDII was very noticeable.
I expected the EDIV to develop these themes, but was quite surprised when - with the brief encounter i had with it at BirdFair - it actually didn't and seemed a much more average product for the money. Really, the things that had made the EDII stand out seemed to have been abandoned. I never really understood this, as the EDII had received several notable plaudits on its launch. I was hoping the IV would have a slightly wider FoV and be a little brighter.
I have no problem with the colour reproduction either. If you're in a mixed environment with close-by and distant activity and have the patience to get used to the speed of the focus (which was slowed in the EDIV as Stephen said) the EDII is a very useful binocular indeed. I'm slightly surprised at reports of problems with them, as both the original ED and EDII have served me very well in a range of uses.