I have a theory about the reason a Constitution class starship was never seen on TNG in spite of the fact that many of its contemporaries were. I beleive it was because if a Galaxy were ever parked next to a Constitution (especially after the refit) everybody would realize just how ugly the Galaxy class is.
I wish they'd made the Abassador Class (seen on screen in Yesterday's Enterprise; then again in DS9's pilot episode Emissary doing an attack run on the Ricard run Borg Cube at the Battle of Wolf 359) the 'Hero Ship' for TNG - I never have cared for the look of the 1701-D Galaxy Class either.
Eh, it was a conscious decision to make a more organic look that was reminiscent of the TOS Constitution, but showed advancement and evolution of design. They wanted something visually distinct for TNG. I also think they also wanted something that was not especially threatening (exploration ship and all) so it lacks the sharp edges and sleek, clean lines of the Connie.
It's not my favorite ship, but it is iconic and instantly recognizable. I'm kinda "meh" on the "saucer separation" version coming out. I look forward to see how that effect looks in game but other than that I am not too thrilled. I would have preferred a three-part, attack-vector Prometheus escort and I am not even an escort pilot.
She does have a bit of firepower, but Intrepids have them beat any day. Who wouldn't want to outmanuver their enemy by intentionally putting your ship smack on the surface of a planet? Sounds more useful than split in two. But each has its ups and downs.