Either would be fine tbh. However, if you want true stability, look for something with ecc memory support (which was one of the reasons why I got the A1Sri). Which, btw you can still buy on Amazon for $250 US. Even if its last gen Atom, its still more then fast enough for a small network. Now, if you were doing more networks, or multiple VPN's with SIP and a bunch of other stuff, then I'd look at more powerful hardware. The only real benefit of the newer atom (unless you go with the 2750), is lower power consumption at 14W vs 20W.