I started out with a 54 while all my shooting buds had 50's. I still haven't bought a 50 yet, rather I bought an additional 54. In the meantime 4 out of my 5 buds have gone back and bought 54's or 54 barrels after shooting mine and seeing how it performed on game.
Not saying the 50 is bad at all, and in fact I still intend to pick one up. But in the small sample of our group, once anyone sees and shoots a 54, they usually mozy out to buy one.
I've whacked a lot of deer with 54 PRB, plus several elk and one moose. Nothing but smiles.
I finally managed to recover a 54 RB from a big deer last Saturday, and it still weighed 204 grains after going through a lot of deer and bones. About as big as a quarter now and still almost 1/4" thick in the middle. Yup, the deer hit the ground like it was electrocuted. Not normal performance for side to side lung shot which have always penetrated completely for me, but pretty impressive performance after taking out a shoulder and a couple of ribs then angling through about three inches of spine (steep uphill shot with the deer quartered toward me).