The P7H55D-M EVO is a Micro ATX board but it is a fairly clean one. As this board does not have options for Crossfire ASUS has some room to organize things and keep them cleaned up.
Taking a close look at the RAM slots and CPU socket we see the now friendly 'one-arm" style slots the 24-Pin power connector and the "MemOK!" button. As we have talked about before you can use this button to overcome issues with RAM compatibility.
Looking at the top of the CPU socket we find the awkward placement of the 8-pin Aux power connector. It is very close to the heatsink and is fairly easy to get on, but a pain to get off.
Down on the peripheral side we can see there are two 4-pin fan headers side by side for extra cooling. This worked well for our Hyper 212 with the extra fan. More importantly we find two PCIe x1 slots, a single x16 PCIe slot and a single PCI slot.
The other side of the board has the SATA and PATA ports. There are two clusters of SATA ports there are four near the RAM slots and another two near the bottom edge of the board.
For I/O ports on the P7H55D-M only two things stand out. The first is the use of a DVI-D port. For many people this means buying a new cable. The majority of cables that ship with monitors are DVI-I. As you can see from the diagram below, well they are not compatible. The other items of note are the two USB 3.0 ports.
To wrap up our walk around, the P7H55D-M appears to be designed for the mid-range home system or perhaps a higher end HTPC. It has enough slots to cover a few extra peripherals like a TV tuner (or two). It has a clean layout so that you can stuff this into a small form factor case and still expect good airflow.