Well, okay, they're not absolute magic before you get too excited
But useful to move around troops and they can pack quite a punch against lesser UFOs. I had a dimension gate hovering right on top of my base for several days (and alien waves) and then the apcs actually
were magic. The first time, the aliens took me by surprise so my valkyrie was launched from the base, the rest of the force scattered in the city. The valkyrie almost was downed during launch and had to flee but the apcs actually turned the tables when they rolled out of my hangar... all in all they must have downed five or six UFOs by now and drew a lot of fire away from the base itself. Just don't forget to unassign your soldiers if you have to send the APCs into battle