The HAF Xb sits relatively squat, being wide enough to accommodate a full ATX motherboard and tall enough to fit four staccked 3.5-inch drives and leave plenty of space above the motherboard for large coolers. After all, a HAF case shouldn't impose hard limitations on the best of processor cooling options. Each of the two sides are the exact same, with a sturdy handle near the top flanked by a large-holed vent with ovalized cutouts. The top panel is essentially one large vent for the addition of a huge 200mm fan. If you haven't used a 200 mm fan before, they are great because they can move alot of air at low RPM, which makes them very quiet, plus they look awesome in their own way. Cooler Master will be offering a windowed top panel in the near future, allowing clear views in at your build.
The rear panel looks very much like a typical case, but lays flat with the power supply just behind (underneath in this case) the motherboard. Just to the side of the processor, three external water cooling holes are found, although they are the punch-out variety and are not grommeted, so it seems Cooler Master is leaving it up to those with external water coolers to file/grommet the holes themselves to protect the hoses. The rear 120mm exhaust and two 80 mm drive bay exhaust fans are complemented by vented expansion slot covers and a large vent above the expansion slots.
The bottom has large padded feet which provide a slightly-raised platform for a down-facing power supply to draw plenty of air and also keeps the case from sliding when on a table/desk top. The power supply intake has one of Cooler Master's awesomely convenient removable dust filters which is removable without even having to lift the case. These have been outstanding for maintaining a build I've had in Cooler Master's Full Tower Trooper for over a year which has a similar dust filter. With a little click you can pull the filter out, run it under some water, pat it dry, and slide it back in.
The front panel is simple, with a large power button, a reset button, audio and microphone jacks, and two USB 3.0 ports. Cooler Master has taken a stance that most of the people looking to build in their HAF Xb will be serious gamers/benchmarkers/overclockers who keep their builds relatively up-to-date and won't miss not having any USB 2.0 ports up front, and for the most part, they're probably right. The two drive bay covers are filtered and removable as we've seen on the Trooper, which is a very handy feature. The other thing we have going on up front is two of Cooler Master's external drive bays, which they refer to as the "X-Dock." The trays have a telescoping setup so it's easy to drop in a drive, slide the pins into place, and slide the drive into the case. This can be handy when transferring data from a backup drive for a fresh install or new build, something gamers and frequent builders will likely be fond of.