The main difference that really stands out between the CUSL2 and the CUSL2-C is the AGP slot. While the CUSL2 follows ASUS tradition and implements an AGP Pro slot, the CUSL2-C uses a universal AGP slot. Fortunately, the notch for DIMM1 doesn't interfere with the AGP slot; on many other 815 motherboards you have to install your system memory before the AGP graphics card (or else DIMM1's notch will get in the way). This isn't a feature per se, but more of a nice touch implemented by the CUSL2's designer.
Plenty of space for larger heatsinks
One area we always watch when a new motherboard comes in is the space around the CPU interface and nearby capacitors. Fortunately, spacing around the PPGA 370 interface on the CUSL2-C (and CUSL2 for that matter) is excellent. We were able to install our Alpha and Golden Orb heatsinks without any problems.
Capacitor is very close
One negative we did miss in our original CUSL2 review was the fan header for the CPU fan. Quite simply, a capacitor next to this header is too close. We had to ever so slightly bend the offending capacitor to fully install the CPU fan cable. This same problem rears its ugly head on the CUSL-C. Hopefully this will be resolved with later revisions of the motherboard.
The CUSL2-C board
While most of the CUSL2-Cs that hit the market will use the 815EP chipset, a few of the earlier models stuck with the original 815E chipset. The reason: ASUS really wanted to get the CUSL2-C out the door immediately. Rather than wait for supplies of 82815EP chips (the memory controller hub used on the 815EP chipset) ASUS decided to eat the cost and simply slap the 82815 chips they had in inventory onto the CUSL2-C boards. ASUS made it clear to us that these boards would cost the same as CUSL2-Cs with the 815EP chipset, so there's no need for consumers to worry.
To power cooling units, three fan headers are present: two located on the top half of the motherboard, and one near the bottom. With two fans up top, one is to be used for the CPU cooling fan while the other can be used for a chassis fan, perfect for blowing fresh cool air over the CPU and graphics card, two of the hottest components in most systems.
Just like every other ASUS motherboard, the CUSL2-C also features a power LED. With it, the light shines the moment your motherboard receives power, perfect for identifying a dead motherboard.
ASUS's iPanel is a drive bay panel that can easily be installed in an empty 5.25" drive bay in the front of your case. With 2 USB ports built-in the front panel, you won't have to reach around the back of your system to access your USB ports. The iPanel also has a large LED display that can be used to show boot errors, system voltages, CPU frequency, fan speeds, and temperatures.
The ASUS iPanel
The iPanel can also be used as a diagnostic LED display. Simply look up the diagnostic error code provided by the iPanel during boot up, and you'll immediately know why your system isn't booting up properly. The iPanel also has 4 hotkeys: two are used to launch your email software and Internet browser, while two hotkeys can be customized to any function you desire.