Montech has created a very good and functional chassis. It doesn't try to push the envelope with unique engineering or even looks, but hopes to offer everything in a case you could want while keeping the price as low as possible. While definitely a great goal to go for, many brands have tried just that and failed.

From an external perspective, the Air 900 looks good—Pure Base 600 good as it is obvious where the inspiration for the design of the chassis comes from. That is actually a good thing as the result is a clean, understated look with soft edges and nice 45° angles. With its mesh front the Air 900 Mesh also actually offers something that its inspiration does not.

Looking at the interior, the Air 900 Mesh employs sturdy steel all around with the metal shroud and assembly pretty traditional by modern standards, with the ability to hold a big enough CPU cooler, long GPUs, and a potent PSU in addition to liquid cooling options.

That having been said, things don't come across as refined upon closer inspection, as you can see the plastic frame through the metal mesh with its opening, unlike the rest of the design. Also, with the wholesome set of I/O in the top, things are decisively simpler in construction than with the Pure Base 600. None of this is an issue really as the case doesn't loose any functionality, keeping in mind that the Air 900 turns out to be around $30 cheaper, which could mean everything to a mainstream builder considering you can invest the savings into more memory or a bigger SSD instead.