I've never tried an ASUS laptop, but I'll say that I've actually quite enjoyed my ASUS motherboard over the past two to three years in my last computer, the M5A99X Evo, and once never had an issue with it failing, though this was for a desktop PC and at the time, was a more higher end motherboard. The only other ASUS product I've had was their dual-band router, which I will say, started taking a shit on me two months after the one year warranty, would constantly drop connection, really slow wired speed, and as soon as I switched to an older, weaker router, my issues were gone.
So, I'm still somewhat neutral when it comes to ASUS. I've had one good and one bad product and haven't tried any others, with that in mind, since you already had to replace the fan, and I know you're someone who takes care of their stuff, it sounds like ASUS doesn't do laptops very well. I would probably get a new one. Save yourself the troubles of switching out the motherboard, and then possibly finding out that it's defected. Oh yeah, remember the motherboard I got? Wing (aka Hellfire Dragon, old, old member), ordered the same one and it was defected when he got it and it ruined his CPU. So yeah, totally leaning towards a new one.