The evacuation scene was nonsense, just staged for the sake of dramatic urgency. All the kids and families should have been in the saucer anyway. Only thing I can think of was evacuating from the outer saucer sections (near the hull surface) towards the inner saucer core for more protection. It's a really big saucer, I can understand a rush to get to the center from the outer rim.
Otherwise, I didn't much care for the saucer crash. Not storywise in the film, not technically for the effect.
I'm the first one to prefer model work over CGI. Maybe it was trubble with the scaling or the lighting, but I never got a sense of the real supposed size of the saucer. I never bought into it as the real thing, I wasn't convinced. I always saw it as an effect, a model shot. I couldn't buy into it as "real", even if I still can appreciate the work that went into the scene.
The BoP landing on Vulcan in TSFS, that looked real. The Enterprise in drydock in TMP, that looked huge and real. The saucer crashing in GEN? Didn't work for me.
And even if it did, I didn't want to see Ent-D destroyed anyway and I didn't like the stupid reason it happened in the movie, so low marks all around for me.