I've never actually seen anything in 70mm IMAX, so idk! But I love the vibe of analog film and the way it looks, so to experience Nolan in the way he intended it at essentially 16k resolution is likely going to be incredible. Five hours is quite a lot though, especially to then watch a three hour movie. Maybe if you made a weekend out of it and stayed at a hotel or camped somewhere? I'm lucky that the closest one to me is only a 45 minute drive