They're both fine, depending what you want to put in them.
The Corsair is cheaper, and has a front and rear fan by default. The front fan is a red LED fan.
The Game Max falcon is a few £ more, has 2 front fans by default (so adding an extra exhaust fan would be ideal), the front fans are RGB LED, and it has a fan controller switch. It has 4 USB ports at the top front (2 USB 3 and 2 USB 2) vs the Spec03 which has only 2 USB ports, both USB 3. The Falcon supports 240mm AIo water coolers.
I just ordered a system from PCS with the Corsair case. Hopefully be here by the end of the week. Its priced well but again, you get more if you pay more in this case.