Just took a closer look at the Asus spec..... Holy cow, that thing is PACKED! The price is incredible considering what would be available 3 years ago. It does have things that you don't need, but it has USB3 plug and that's a good thing!
Asus has slower processor than the Mac if you opt for the 2.3GHZ version.
The Mac has thunderbolt which is twice as fast as USB3, but that's provided that you have thunderbolt devices. USB3 devices are also compatible with USB2 devices, which are everywhere.
If you want a really smooth operation with as little disruption as possible due to memory inefficiency, I think you need at least 8GB of RAM, with options to upgrade in the future. The Asus has room to upgrade to 16GB whereas the Mac maxes out at only 8GB.
Graphics card spec is also important. The memory spec on graphics card will directly affect your work flow. For example, when I apply a large brush over my image, I usually don't see the movement of the cursor and have to wait for a second before the effect appears on the screen. The missing cursor action is because my graphics card can't catch up. The delay in the final effect being shown is the processor speed. When choosing graphics card, you want to get those that are independent, not "integrated" ones. The independent ones have their own processors, which means it helps to lighten the load on the main processor so your computer don't choke and freeze. The Asus graphics card is for hard core gamers, which should be more than enough for your purpose.
The Asus graphics card has 1.5GB RAM vs Mac's 1GB.
The Asus packs MUCH more computing power than the Mac at much lower cost. They are really not in the same class.
I would have to say, if you look at smaller screen size laptops, you won't find the same specs due to size constrain. The mother board on a smaller laptop may not have the space for the extra RAM slots or cooling fans for heavy duty processors or graphics cards. So if you are not looking to be carrying it around, may be you should be looking at a desktop with a nice monitor.