Purchased a 60x10.4 for my 2017 Forester and it looks great! It adds some nice character to my Forester and really fits the style/mood of my vehicle (and perhaps many off-road vehicles as well). Due to the large size, I would highly suggest getting at least 2 (perhaps 3) people to assist with installation to avoid any mistakes.
So for me, I got the 70" decal. The instructions and installation videos all are great, but I'll say installing a 70" decal by yourself is difficult. I thought I could do it but had some issues. I also have some contours along the doors of my trucks that proved a little difficult as well. When I asked my wife for help on the other side it was loads easier. Also, I'd recommend not installing in direct sun or on a particularly hot day. As the "paper" backing dries it tightens or shrinks and can pull the vinyl off the vehicle so you have to constantly pay attention. In the end, the vinyl is on and it looks great. I think it adds a lot of character to the truck and I couldn't be happier.