Zyko :
But if put a fan like under the laptop, is it going to be ok or it is still gonna be hot as heck
A cooling pad....Don't use the fans as they do nothing and actually some times suffocate the parts due to their airflow. But the cooling pad as a mat to keep the laptop high off the surface its sitting on is what i'd recommend. As for hot as $%&%, if your gaming or using cpu entesnive programs, then yes it will run hot, and several users post thermal throttling which is actually what should happen with that laptop. But even while thermally throttled, you'll still be getting good performance out of the msi. The cooling boost fan mode, from what users have told me, works great and keeps temps down, but sounds like a hair dryer and well noticeable with headphones on or in another room. But it is an option. Fan noise in general will be louder due to a single large fan trying to cool two very heat producing comonents so close to eachother.
But all this said, you wont/shouldn't have any 'issues' major wise with the msi. Yes it will run hot, yes you will get thermally throttled (how often dunno but not all the time), the build quality will be good but not great, but for your money you'll get the most for it.
With the asus, you'll get (I imagine) a 20%performance hit, yet still will play high settings on most games. But you'll get a cooler, quieter, and nicer build.
You just need to choose, performance for quirks, or solid build for performance hit?
All this is relative to one another, each laptop will be great, and you'll enjoy whichever one you pick.
I prefer asus, but I video edit and 3d render for hours each day which puts max load on the system, my asus runs hot and fans kick very nicely, I can only imagine how bad the msi would've done for me, hench why I gave up msi gt70 dominator with 8gb gddr5 880m graphics, for the same priced asus with 3gb 870m. But what I do puts 100% load cpu and gpu, gaming will only do like 50% cpu 90-100% gpu. But I image you'll run 90-95c temps on msi during hour long gaming, which is what I run rendering so end result same. So big negative on the msi, yet it will offer the Maxwell 860m beast of a gpu, which in my eyes makes the heat and fan noise equal.