I prefer the .243 for predators and deer. My experiences have been good. .243 has tons of bullet options factory loaded. For a deer rifle it penetrates using a 100gr soft point very well. It is the ultimate predator/varmint rifle, to me, for it is flat shooting hard hitting, and bucks the wind pretty well. I shoot 55gr Nosler Varmegeddon ammo for predators/varmint. The round penetrates well before expansion unlike the more traditional varmint cals shooting varmint bullet. Often I refrain from shooting fox but I have shot some with the .243 and the Varmegeddon bullet. The combo has only "blown up" a few. Most have not even had an exit hole. It shoots coyote dead too. Then gun has some reach for varmints and predators also.
We all tend to over think things. This debate over caliber size happens on every predator forum and deer forum I have ever been on. Before the internet this conversation lived in every hunting camp and club. This is physics question really. There are a ton of variables. It would be very difficult for someone to cover every possibility in their lifetime.
Recoil matters, but I think we all give it too much attention. I would not give a 6 year old child a magnum cal (I think most adults struggle to shoot large magnum cal too) but I would not split the hairs of 7mm and 6mm. The kid wont either.