Software-based Border Router

Hi All! Just want to ask if anyone here had experience deploying software-based routers to serve as perimeter / border router? How does it gauge with hardware-based routers? Any past experiences will be very much appreciated. I wanted to know because we've been asked if we want to assume full control of the internet link (up to the router). By assuming control up to the router, we still want to configure iBGP with our parent network so that we can take advantage of some routes available to the parent network's gateway. The saddest part is presently we do not have the router to serve as our gateway this is why we are considering the use of software-based routers. Thank you.