I have to agree with Darren. Besides what Darren mentioned i add another one.
Another difference is that Pluto comes with it's own operating system and it's free, and that piece of software needs windows to run.
with pluto you have no limit regarding devices support. a new device can be programmed (by us or by community) and create support for it with minimum effort.
You have to understand Pluto as a Core, the main router does all the tricks, communicating with devices (network, bluetooth, ir, rs232, usb, firewire), sending alerts, media streams, etc.; so the main frame is there and working. That makes adding new devices just a routine.
For example you want to control a new tv that just came from the factory.
You just need to create a new device in Pluto, that inherits data from a device template, give a name, choose the way how it works (lets say ir) and later learn the ir codes from remote in pluto. that way you can control the tv without having to use the remote again. plus that you can share the codes to other users so they benefit too from your initial effort to learn ir codes.
hope make sense,