I have an US Scorpion. It's been to a few different conventions, and amused some police officers, but the only times I've been told a direct no into taking it anywhere was the movie theater. At the renn festival, they told me I may have to peace bind it if any of the security had a problem (I'm still lost on this; I guess they would stick a tennis ball on the end).
The last convention I went to, I was taken to Con Ops for them to examine my blaster to make sure it didn't actually fire, and they said the saber was 100% okay -- and asked if they could play with it.