Cooler Master HAF-XB Computer Case Enclosure

Computer Case Final Thoughts
Although the design of the Cooler Master HAF XB is unusual, it's not unique. Lian Li's PC-343B case uses a similar design, as do custom cases like the Mountain Mods U2-UFO series. But these cases are very expensive, with the Lian Li going for $300 and the Mountian Mods cases for potentially much more, depending on the options you choose. The HAF XB, in contrast, costs only $99.99.
Cooler Master pitches this case as a "LAN box/test bed", which initially sounds silly: LAN boxes are supposed to be small and easy to transport, while test bed cases are generally open-air designs with dangling cables and bits that make transporting them clumsy when they're loaded with components. I was surprised to find, however, that Cooler Master's assertions are completely valid: the rigid steel frame and large handholds in the side panels make carrying the case much easier than carrying a traditional tower case of the same weight, and although it wouldn't be my first choices for a test bed case, it takes only seconds to remove the slide-off top and side panels and gain full access to most of the components you'd need access to in a test situation. In fact I used the case for a test bed for my AMD FX-8350 CPU review and the ease of swapping out the processor in this design made it a good choice.
cooler_master_haf_xb_back_top_built.

Given the price and features of the case, it might seem picky to complain, but I would have liked to see an eigth card slot, since there's plenty of room for it; and a few more front panel ports would have been nice, too. And although there's an easily removable filter for the power supply air intake, the front panel fan filter is non-removable and built into the front panel, which requires that you remove the top and side panels to clean it. Last, I'm disappointed that there's no easy way to accomodate a 3.5" device like a card reader or fan controller in one of the 5.25" bays; and the inability to secure both sides of a 5.25" device means that even 5.25" non-drive devices won't work well.
But these are minor complaints. The design of the case means the entire width of your motherboard area receives airflow from the front fans; it has plenty of room for most builds, its design confers a number of advantages, and best of all it's priced very reasonably.

HAF XB Conclusion
A computer case's main purpose is simply to hold your components. Beyond that, there are other considerations, but these will vary depending upon the use you put the system to. For example, thermal management and airflow isn't very important in a low-powered HTPC system, but is critical for high performance systems. And if you're building a high performance system, you've probably checked out Cooler Master's other HAF series cases, all of which are designed to provide high air flow. However, while a traditional tower design places the drive bays between the front fans and the rest of the system, airflow from the HAF XB's front fans has an unobstructed path across the width of the motherboard. This is one of the very best cases I've ever seen for air cooled systems, rivalled only by some of Silverstone's Raven and FT cases with their rotated motherboard design.
The HAF XB shares its "industrial look" with the rest of Cooler Master's HAF series, continuing the line's blocky surface detailing and flat black coloration. It is a striking case only because of its unusual shape, and probably only computer geeks will be impressed visually...most people will see it as just some black lump. One aesthetic point is dust collection on the front panel: there's visible dust on the front panel of my unit after only a week of use on a desktop in a relatively low-dust environment.
As you might expect from Cooler Master, the construction quality was very good. All the parts fit smoothly, and the steel design is very strong. With the top and side panels off, the temptation is to pick up the case by grabbing one of the top rails, but don't worry: even a single rail is easily strong enough to bear the weight of an entire loaded system with no discernible flexing.
The HAF XB is more functional than most tower cases, especially if you include things like "ease of transport" and "ease of access to the motherboard components" in your definition of "functional." Some might argue that it's easier to get at the motherboard in a tower case with hinged, swing open doors, or at least as easy if the tower case side panels come off easily. But then you're left with the reality of a tower case: the motherboard's positioned vertically, and that makes getting components in and out harder than it is when the motherboard's laying flat. That's the reason why you'll never see a test bed case that mounts the motherboard vertically. The only functional concession this case design makes is the limited number of 3.5" and 5.25" devices you can have, and even so, the ability to add four 2.5" devices helps if you need more hard drive room. This is also the least expensive case I've seen with hot swap drive bays.
The value: ah, the value. I admit I was surprised by the relatively low cost of this case. For what you're getting, I think $99.99 is a screaming deal; I have reviewed other cases at a similar price point that offer nowhere near this level of function and convenience. Cooler Master's HAF series has always been about a good price/performance ratio, but I think this one hits it out of the park.
If you've the desk space for it, and you like easy transport of and access to your full ATX system, this is the best case on the market for you now.

Pros:
Benchmark Reviews Golden Tachometer Award
+ Unusual, visually interesting design
+ Exceptional air flow across the full width of the motherboard
+ Hot swap bays for two 3.5" drives
+ Easier to build a neat system 
+ Very sturdy construction
+ Actually can be used both as LAN box and test bed
+ Excellent price/performance

Cons:
- Only two front USB ports
- Only seven PCI slots
- No easy way to accomodate non-optical drive devices in 5.25" bays
- Takes up a lot of room on your desk
- Must remove front panel to clean its dust filter

Ratings:
  * Presentation: 9.00
  * Appearance: 8.50
  * Construction: 9.75
  * Functionality: 9.75
  * Value: 9.75