Personally I wouldn't buy either of the ones the OP listed.
Acer = Cheaply built
imo, used to work in laptop repairs and the sheer amount of Acers we used to get in was unbelievable. (I do admit however that Acer seem popular laptops and it could have been a case of high saturation of the brand rather than they being so unreliable)
Sony = Parts can be a nightmare to get hold of, and in many cases extended warranty companies won't do the repairs themselves they will send back to Sony, who do not rush in sending stuff back, you could be months waiting to get it back should it need to go in for repair.