NZXT has done a good job in offering an entry level family of cases by introducing the Source series. On top of that the H2, Phantom 410 and Phantom all have obvious reasons to be part of the NZXT line-up, but the Tempest enclosures on the other hand do not seem to fit into the strategy of NZXT at all. Both the Tempest 210 and 410 are too expensive for what they offer and when looking at the Tempest 210, NZXT is giving the end user a much better choice with the Source family of enclosures at a much cheaper price point.
I would not be willing to pay 10€ more for sliding locks on the front drive bay covers and a bigger vent on the side of the chassis. NZXT should have tried to include more I/O in combination with an additional fan, to give the Tempest 210 a few factors to set it apart from their more affordable enclosures. While the NZXT Tempest 210 is an adequate choice, it does not really have a reason to exist, especially as the looks and price/performance combination may veer many buyers away from the case and into the arms of the NZXT Source lineup, while still leaving these customers enough money for a dinner at the diner around the corner.