If there is very little in it technically then your next concern should be after sales support and warranty. Can your son get a better or longer warranty on either of the machines in Malta? Perhaps one of them will supply home repair instead of returning it to the shop, or maybe give an extended warranty for free.
Asus once had a good reputation for quality of build, but I am not sure about the latest models. Home users in Europe have indicated that Dell after sales is poor but Business users say it is good.
Personally I have become a fan of Lenovo and family members have had good experiences with their machines.