We should judge the Cooler Master Mastercase 5 from two different vantage points. There are, on one hand, those who buy the chassis because they just need a case. On the other hand are those who want to customize it to fit their needs. Let's start with the traditional customer.
To such a customer, the Mastercase 5 is at the higher end of the mid-range segment with its 110 USD tag, which is just above that magical 100 USD barrier. For its price, the chassis is actually extremely potent and very well constructed. Cooler Master has done a great job with the tooling and engineering. Every feature seems to be well thought out and implemented. From the possibility to add a large radiator, on to the numerous mounting holes for drive cages, or that PSU divider - everything works well. The same goes for the way the SSD trays are designed, as they lift the drives off the surface slightly to allow for SATA cables to be attached without putting any strain on the connector itself, an issue many other implementations tend to ignore. To keep things clean, there are openings in all the right spots within the Mastercase 5, and the two included 140 mm fans are appropriate for a chassis of this price range. The uncomfortable handles and the somewhat loose ODD-locking mechanism are no deal breakers, far from it. The first is not an issue you will have to deal with every day, and the second can be resolved by using a single screw or two.
Now, from a modular perspective true to Cooler Master's new slogan "Make It Yours," the Mastercase 5 is supposed to disrupt the case market by offering something amazingly new. While it does allow for above-average customization, Cooler Master has in essence taken the traditional approach of "one frame, many configurations" manufacturers attempt to adhere to in order to service several price points - but as a feature consumers can now directly tap into. So while Cooler Master is still offering the same frame in three different variations that use the same components in the Mastercase 5, Mastercase 5 Pro, and Mastercase 5 Maker, the small but important differences can now be bought in retail as separate parts.
Manufacturers usually shy away from such an approach as more SKUs translate into more listings and more work for distributors and the retail channel, but Cooler Master has taken it upon themselves to alleviate this issue a bit by offering a retail system for brick and mortar stores, while working with online shops to present the chassis for what it is, with the ability to even customize it before you make the purchase.
In that sense, Cooler Master's "maker spirit" is there, but there is no "disruption" yet, though the chassis is a step in the right direction. A more important aspect of the whole Cooler Master makeover is their new brand focus and product structure. How it will evolve will be interesting to see. With that said, the Cooler Master Mastercase 5 is definitely an excellent chassis for a great price, regardless of how you look at it.