Hi,
It is not recommend to leave any device powered on for an extensve period of time, especially not one that doesn't have active cooling system like server machines. The hardware upon which the same is built on can prove to be also not that durable and you'll experience a device that doesn't live very on. A solution to this "issue", which comes at the lower price for the device and the unmatchable performance, is however a simple usage of a power conditioner like Furman. Hook up all your outboard hardware (mine also harbors the PC, monitors and lights in the studio), as well as the Presonus Quantum 2626. Leave the 2626 turned on and every time you shut down your PC and the rest of the hardware, just turn off the power conditioner. You'll save power, as well as a hassle of pulling the device from the rack out to be turned off at each session end. Hope this helps. Cheers!