I just went throught this process, And I mean in the last 2 weeks. I myself purchased the IPC. A large reason for this was simply networking. The Roadhog does not have networking capabilities. Means no focus remotes, no visualizer connectivity. for me that really was enough. They booth support 3 monitors. The IPC has this built in, the road hog needs a USB adapter. The roadhog does have more under the hood but I personally can not tell you what the large difference is.
Here is the thread i started that will probably answer most of your questions.
I'm operator on grandma and I first want to buy for learn it. I'll use it for all shows I'll made: concerts, events, dance, theatre. I know Roadhog haven't ethernet but I'm not sure hog3 can do different worlds with several desk on the same show. So if 4 universes is OK, what the interest of ethernet, except use visualizer? Maybe IPC has not the same after sale service than Roadhog...Maybe future soft will be only compatible with roadhog, full board and hog3? Do you think I'm wrong? (sorry for my poor english!)
A large advantage of having the Ethernet port is the ability to do remote focus. A laptop on a wireless network can be used. The PC software is free to use in this manner.
Another reason for Ethernet is to have more then one console on a network. If you are ever crunched for time or just have an extremely large show, you may want to bring more programmers based off the same show file. Is that what you mean by Worlds?
Network backup is on the future list of functions.
All the consoles use the same software. They are all different hardware bases. My understanding is that the IPC will continue to get all the available updates as they come out.
I imagine that the IPC was discontinued based on newer hardware with more power coming out. Thats just my guess tough. An HES rep would know the real reason.
The Ethernet was a big deal for me specifically. I generally don't have a guy to run the desk well I focus, so the ability to walk around with a tablet pc or a netbook or my phone was very important.
Yes I spoke about more programmers based on the same show when I speak about worlds. On grandma, you can distribute or partage your fixtures with other programmer in the same show. You say network backup is on the future list of functions, would it be be for v3 or next? That I would like to know is if Roadhog and IPC are so reliable. It seems a lots of people had problem with last version and their mothercard with IPC. Will it be set? Thank you