I got no experience on both manufacturer ~
But if u based on spec , Asrock Z87 Extreme 4 got better on-board audio chipset ~
Others spec , they are quite identical.
And if u care about how the mobo looking , Gigabyte GA-Z87X-UD4X , which I think it got better looking ~
Btw Asrock cheaper is because its only got 1 year warrenty for its product , if I didnt remember wrong so it can cut cost and better chipset on the mobo ~
What is your system specs ? A Z87 MB is for overclocking, if you are not into overclocking and not going to do SLI then those MB's are waste of money.
I wouldn't be doing sli but I might want to in the future.. and I wouldn't be overclocking but I might want to in the future.. so ya. If z87 is out of the picture, what MB would you recommend? (preferably gigabyte)