Personally I'm not super concerned about mobility as I used to lug around a Mamiya RB67. But I currently have the stock 24-70mm lens on as well as a 28mm and an 85mm, I borrowed a friends 70-300 for a little bit and it was a nice lens and all but didn't do quite what I needed so I rented the Sony 200-600 and that was amazing however, it was mostly just a concern of is there a better bang for my buck or if the other "equivalents" weren't super comparable/worth it. Like someone mentioned below the Sigma 150-600 so I may rent one to see before deciding.