I am not an owner yet but have played with with the .416 a bit. Not pictured is the Weatherby but I did not care for the rifle so I sold it after a short period. I know the caliber was excellent.
Here are some images of options I have enjoyed.
I am not home with my reloading notes but these are pretty common and easy to find data.
The .416 AR was developed by Jeff Smith over on Accurate Reloading.

I too have been thinking of the new Ruger but it really does not fill any voids in any of these calibers. I would think it makes more sense to go with a rifle which really fits and then reload to suit your needs from light .416 Taylor to very heavy AR. The Rigby handles it all with a bit less pressure.
Of Course the Ruger RSM is a bunch better rifle in my opinion but heavy. My Taylor was inexpensive built on a vz24 and the AR was built on a Ruger 77 tang which is my favorite. My .416 RM was on a model 70 but I just didn't enjoy the idea of high pressure while getting ready for Africa.
I plan on handling the Ruger .416 a bit to see if it fits me and will probably decide then to own or not.

Frank