Took my 11yr old ds2 and we loved it. There was a certain amount of cowboys and Indians hacking and slaying, so not surprised its a 12a. I thought it was a fabulous film, but I'm old enough to remember the tv series and it made me feel 11 again.
Yes I went yesterday with 13 yr old DD and we loved it. It's a slightly silly action movie with lots of chase sequences, shooting etc. there's reference to a particularly grisly act but it's not shown. 12A seemed right to me.