That Constellation has unfortunately some very outdated graphics, especially for the external model which looks like early FS9 stuff. I never saw many screenshots of it. In fact, the simmers preferred the freeware Constellation by Manfred and his team.
From my side, I couldn't decide between the two of these. The external model of the Payware Connie prevented me from buying it, but now it's one of the default planes in P3D, so I could finally fly it. What I like about it is the complete virtual cockpit, which includes the engineer panel, thus allowing a complete start from Cold&Dark.
The last version of Manfred's Connie I tried had an incomplete VC, the engineer panel was not available or not clickable, so a Cold&Dark startup was impossible from the VC.
Perhaps there are some additional or more valid reasons, like bad paintkits or bad texture mapping (mirrored, hard to edit, etc...) or stuff like that. Potential repainters would be able to explain this much better than myself.
It's a shame because a good repaint would probably compensate for the lack of polygons...