This is a no brainer IMHO. ASUS has been making MBs for many years. Azrock only a few years. When Azrock has as much experience as ASUS I will buy their MBs. A bargain isn't what you pay, it's what you get. You must live with what you buy long after you forget how much it cost.
Here's the 'thing' ASUS produces higher-end and superior component MOBO's so the 'fine print' is where ASUS shines. That said and for a K CPU the only MOBO you linked that I would consider using is the ASRock Z77 Extreme4. However, for long-term I'd consider the ASUS P8Z77-V or ASUS P8Z77-V Pro, so the question is -- is $60-$70 worth it to 'you' -- to 'me' it is.