You're basically paying the money to have someone to blame when it stops managing that traffic, I think.
I was involved in a commercial-grade web service setup many moons ago that used a few of them, but they arrived pre-set in whatever configuration they were supposed to have. They are appliances, probably just some small custom Linux or BSD system in a funny looking case. I just plugged stuff in to them and magic happened.
Which, admittedly, is probably exactly what you want.