I am a college student that has grown up on Canon cameras. I love to travel and am on a college nordic ski team that I take pictures for whenever I get the chance. I am looking to upgrade from a Canon M5/Canon 7D to a Sony full frame mirrorless. I am wondering if the early models (A7, A7R) would be a significant upgrade in focus speed and image quality or if I should wait a couple years to save for the most modern A7r of the day? I would like a camera that has the ability to print large photos but otherwise just want something durable and versatile.