I bought this laptop last week and in another forum read posts by Asus person saying that is a discontinued model, Why? Doesn't inform but it's inconcebeable that a recent laptop with good skills get out of race too soon.
I'm worried because hate Win 8x and change the hard disk and installed an AData SSD for Win7x64, but lack of drivers. I started saturday so need more time to get it 100% functional.
I suspects that you grandson is like my daughter, she plays Minecraft and download lot of mods. The modest i5 laptop (don't remember his graphics card) almost burns after 45mins. When she unplugged from AC adapter, the cpu reduces his speed and power, but works over 30% (measured in task manager "TaskMgr"). The battery duration is too short, and practically drains to the fan, frequently need remembered that must use a fan base to avoid injuries in her legs. When she plays in my HP dv6 (i7 with 8MB, shared graphics) occurs the same, high power demand from CPU by java.exe.
Meanwhile notes low fps, "lagging" and freezes or even crashes when load many mods. But this happens by a conception mistake: MINECRAFT isn't a AAA game or requires a heavy graphics card... MINECRAFT RUNS IN JAVA and only demands a good processor instead good video card. If you see carefully, the graphics seems "primitive" squares. There aren't physics particles, reflections and so on, the principal fact is the interaction between java objects (classes). The "mods" are huge collection of java classes ( materials, objects, definitions, behaviors, animals, rocks, fossils ).
The main resources than demands are CPU megaflops and with 8 MB RAM minimum. I 'recommend' a desktop because has better i7's versions. If asks for laptops look with suffix M/Q not "U". "U" means mobile platform for basic demand and low power, "M" or "Q" offers better performance. Don't worry about the graphics card for Minecraft. The desktop will give better power for mods.