Hey,
Is the Asus Zenbook i7 Processor "U"? If so, it's not truly an i7 Quad-Core Processor, it's designed for battery efficiency, which hinders performance in comparison to i7 "HQ" Processors.
If the Acer Aspire is an i7 Intel Processor "HQ" (For example, 4700HQ), I'd go for the Acer. The difference in performance is monumental! However, if it's the same processor type, then I'd go for the ASUS Zenbook (Better build quality).