Hasselblad X1D + Hasselblad XCD 21mm f/4 Aperture Series: Ellery Lake
See my Hasselblad medium format wish list.
This series looks at far-field performance with the Hasselblad XCD 21mm f/4, a notoriously difficult challenge for all lenses.
Hasselblad XCD 21mm f/4 Aperture Series: Ellery Lake
Includes images up to full camera resolution at f/4 and f/5.6—all that is needed for stellar performance across the field.
The Hasselblad XCD 21m f/4 would be my #1 pick for the X1D because wide angle lenses this good are not easy to come by. See my Hasselblad X1D wishlist.

Hasselblad X1D + Hasselblad XCD 21mm f/4 @ 18mm equiv (21mm) ENV: Ellery Lake, altitude 9700 ft / 2957 m
focus on rock outcrop near center
[low-res image for bot]