I would base my choice purely on looks. The SCAR-H SSR just looks so badass! And also, since you're buying it used, the previous owner knows exactly how it performs, what have been done to it and such things. Buying a new rifle means that YOU have to find out what parts are not performing as they should and what not.
Unless it's a SCAR-H SSR in tan... If it's black i wouldn't even consider the SR-25.
Unless it's a SCAR-H SSR in tan... If it's black i wouldn't even consider the SR-25.