Sorry for the untimely reply, but yes, the 4240's are implemented for a customer at work.
Initial configuration of the devices is as straight forward as doing an inital config on a router with cisco's setup wizard - obviously you can get more complex if needed, but for simple SPAN port monitoring it's as simple as it gets.
As for implementing the whole cisco suite of programs to support the sensors, I really couldn't tell you, as I'm not part of the operations group that supports these devices long-term.
