With regard to the Excelsior, it is IMO, a lesser design than the TMP ship. The nostalgia for the design, is probably driven by just that (i.e., nostalgia) compounded by the fact that we never really saw it on screen that much and never as the hero ship (the grass is always greener...). I think the Enterprise B was an improvement of the design, but no, it's not worthy of the iconic status that the TOS and TMP ships achieved.
To each his own. I personally loved the Excelsior from it's first appearance. It's sleek and looks fast standing still. I can't stand the travesty that is the "glued on bits" look of Ent-b.
Baby, you and me were never meant to be, just maybe think of me once in a while...