These minis pack a mean punch.
The Zotac H67-ITX WiFi has a little more upmarket feeling to it, simply by looking at the layout. While it looks the same as the ECS H67H2-I, the Zotac H67-ITX has main differences: the 802.11n WiFi adapter and the extra USB 3.0 header (for 2x USB 3.0 ports) next to the Southbridge chipset. The smooth looking heatsink on the Southbridge plus the additional one on the VRM capacitors may provide for great cooling, but it did prove somewhat difficult to install the XTS100H cooler on the Core i7-2600K. That said, this kind of cooling solution is in appropriate for an HTPC in the first place; you’ll be fine with the stock CPU heatsink.
Speaking of extras, the Zotac H67-ITX has 4x SATA II (3Gbps) & 2x SATA III (6Gbps) ports, 1x eSATA, 4x USB 3.0 & 8x USB 2.0 ports. Plus there’s the display outputs (DP/DVI/HDMI), a GB LAN port and 8 channel audio out.
As you can see, the Zotac H67-ITX WiFi is filled to the brim, which is why it looked even more ridiculous than the ECS H67H2-I when everything was set up for testing.