I'm looking at swtiching to dish from Directv. Trying to decide what to get. Not sure I need the Slingbox feature but it looks neat. Now what are the advantages/disadvatages of buying a 922 vs getting an add on Slingbox? Looks to me like the bigger hard drive and better menus, but an add on will work in the future with other unit if I don't like Dish and switch back in a couple years. Does that about sum it up or is there something I'm missing.