I love my 257AI's, but true be known, they only provide about 50-100fps more than the standard Roberts, loaded to similar pressures. The real advantage in the AI case, IMO, is that you "never" have to trim the cases.
Sounds to me like forming the cases is a PITA for you, so I'd recommend just getting a standard Roberts, or if you want a little more zip, get a 25/06. No case forming required.
