So, besides, the OC:
The H97 has DVI and VGA outputs for the onboard video, unlike the Z97.
The H97 supports Intel Small Business Advantage 2.0.
The H97 only supports up to 1600 MHz RAM, while the Z97 supports up to 3100+.
And other stuff, probably, but here's the links to both's specs:
http://www.asrock.com/mb/Intel/H97%20Pro4/?cat=Specifications
http://www.asrock.com/mb/Intel/Z97%20Anniversary/?cat=Specifications