I would like a larger sensor, and the ability to use more of what the lens is seeing. The color distortions that the larger sensor might bring out with wide-angle lenses would have me wanting for a larger pixel count. The longer base length would be nice also, as would a larger buffer. Mine has filled its craw once or twice while shooting action. A diopter adjustment on the eye piece would be welcomed (my $10 FED has one, why can't my $$$ RD1 have one too?).
Most of all, I want a proper service network. If my Honda develops a problem, then I take it over to the dealership to be repaired with the full faith and backing of the Honda Corp. The camera should be the same. Epson screwed up in treating this machine like it was one of their printers.
But most of all Santa; I would like for goodness and the peace that passes understanding to find us one and all, and for all of our surprises to be happy ones.
