I own an iCom IC-A24 and love it. I don't have any experience with the VXA-300 but I own a VX-7R handheld amateur radio made by Vertex Standard, the same company that makes the VXA-300. The VX-7R is Vertex Standards highest end amateur radio, but I think the iCom is a better radio overall.
I would recommend IC-A24 because I think iCom products are generally higher quality than Vertex Standard, I'm sure their both great radios though.