I've been using iLok for some time now for EWQL and Synthogy products, so it's just one more license for me. But I understand your concern. I too have decided not to install freebies like this in the past.
One thing that I find useful is to toggle off all the services/drivers that I don't need using a program like autoruns. This way the additional functionality is only a single mouse-click away when I need it, but not running when I don't need it. I also use a USB port with individual switches, one of which contains my iLok. That too only gets switched on when necessary.