insurrection ended up being virtually nothing, but they did attempt to do something different and not just replicate the tone and scale of first contact. nemesis feels like the producers copping to "ok no one liked insurrection so we should just go back and just do what first contact did". problem was, it was all superficial. they didn't mine what made first contact great, they just took the trappings and left the emotional core behind.
so we get scenes with shinzon saying "resistance is futile" because man wasn't first contact great?
I know I'm in the extreme minority in this opinion, but I actually believe Nemesis has a reasonable emotional core and a good amount of heart in places. To your point, not as well executed as FC...but certainly not non-existent.
And, Insurrection was perhaps different from FC, but it was exactly the same (virtually indestinguishable) from about 170 television episodes...and it didn't really strive to be anything ambitious, which is more what I meant.