Yes, I meant to say that the CdC screenshot shows UCAC3 in conjunction
with the bright-star catalogues. (For instance, you can see that Aldebaran
is shown on the chart.)
As for UCAC4, it does fill in some stars missing in UCAC3:
http://ad.usno.navy.mil/ucac/readme_u4v5
But CdC restricts downloads of UCAC4 to only stars visible from my
latitude -- until they remove this restriction, I'm sticking with UCAC3.
If you want to compare star fields in planetarium programs, one suggestion
is to burn a live DVD of Distro Astro 3.0 and try it out without installation. It
has Cartes du Ciel (with a large custom DSO catalog), KStars, and Stellarium
already installed, but only the brightest stars of the minimal installation are
included with each program. Then compare the star fields in each program
with photographs.
-- sutekh