The personalisation of the place.
There is a tendency to get caught up in the technology of warfare, particularly when you can have the "big" exhibits. A plane hung from the ceiling, a tank you can crawl around in.
Here they had that but managed to tell the story of a people both betrayed and beaten but never defeated without glorifying the struggle.
I can't say anything in particular impressed me, it was an overall feeling. The fact they did not skip over the complicity of the poles in some actons, even though the deaths caused by them (maybe 1,000?) pales into insignificance next to that caused by thrir neighbours.
This is no rabble rousing flag waving display, although the final film is that, but an in depth look and attempt to get you to feel a little of what happened.
I had a good time visiting the Warsaw uprising museum. Modern museum, with lots of interesting writings underpinning the various objects very nicely displayed. If you have the opportunity to pay a visit to the capital city, I would recommend.