The heart of Insurrection for this fan is not stopping the bad guy. It's something Picard says in the first few minutes "Can anyone remember when we used to be explorers?"
This entire movie is showing Picard and company as more than soldiers in a war with the Dominion. It was a nice counter-weight, at the time, to Deep Space Nine, a show I love, but not much exploring done on that show, at least not in the TNG way.
Picard learns about the Ba'ku, Riker tells us about the Son'a. Geordi is there to tell us what he thinks of Starfleet's plans. "I have eyes, but how can I look at another sunset knowing what my sight cost these people." The moral conundrum is this movie, not the bad guy and not wanting to age. Both deal with people obsessed with the one thing we can't have--immortality. But that's where the comparisons end.
And as for plots being distinct, Star Trek I and V are almost exactly alike, with a few pieces moved around.