Both use basically the same CPU and they also use the same GTX 970M graphics chip. Since they both have over 8GB RAM they will perform the same in pretty much any game and there will be no difference between the two.
Get the cheaper one, which is the MSI GT72 GT72 Dominator-406.
I know the MSI laptop has a Killer NIC network manager (possibly the ASUS too, I'm not sure). Personally I'm not a fan of the killer NIC software and have had a couple issues in the past with it defaulting to "eco-mode" every time you start the laptop.