They are the exact same formula. Proraso reformulated in 2012. I think it took almost a year for the reformulated Proraso to end up in C.O. Bigelow tubes and on shelves, but I'm pretty sure they are all now reformulated. When Proraso reformulated, they went to the barbershop-looking stripe motif with the more blocky letters. The reformulation was done to remove SLS and parabens so if you see those ingredients on your C.O. Bigelow box you know you have the old formula.
In my opinion, whether you have C.O. Bigelow or Proraso or old formula or new, they all work great and I would use any of them without hesitation.
When was Tetrasodium EDTA put into Proraso?