I would pick the standard 300-win mag, I have shot one for about 20-years.
I have though long & hard about a 270, 7mm or 300-WSM. I have put the ballistic tables side by side & the rifles side by side. I like the idea of the short mag but I see no advantage to owning one.
Look at the ballictic tables, shoulder some rifles & then look at ammunition prices.[]
Comparing the ammunition prices & the ballistic tables head to head did it for me.[]
Good luck