Aspire/Yoga?

Having just recently gotten a deal for the Acer Aspire S7 (2013) 13-inch at just 1100 USD, I was elated. However, I have held off getting the S7 as the new Lenovo Yoga (Ideapad and Thinkpad) just came out with Haswell. Which one is better?

I'm looking for good build quality, spacious keyboard/touchpad, screen quality and value for money (the Yoga might have the upper hand on that one).

(I personally prefer the Yoga's form factor but am worried about the Thinkpad's build quality. Also, the Yoga is available in October whereas the Thinkpad in November.)

Thanks!