sharke
I was reluctant to install it until someone pointed out that the iLok software was no different to having the NI service center installed, which I have had for a couple of years. It's certainly not going to harm your computer.
I have the iLOK software installed mainly to allow me to use VI Labs True Keys in the UVI Workstation. My experience with it has been that whenever UVI or iLOK update their software, my UVI Workstation will no longer function until I install the updates, and so far the updates inevitably force a system reboot after installation which is frankly a PITA in 2014. So my experience with it has been that it is unlike the NI service center in that regard. When Native Instruments comes out with an update my installed virtual instruments continue to function.
Regards,
Don