I just installed a bunch of insteon dimmers and relays in my place. I'm actually just using them with X10 right now, but the setup has been quite simple. I'm thinking about getting the insteon RF plug ins so that I can get a full fledged insteon network going.
Right now the only issue I see is a limited number of control options for insteon. They don't have the insteon equivalent of the handy X10 RF wall switches or IR to X10 converter. This isn't too much of an issue because the insteon devices can be given X10 addresses. However, because the insteon RF repeaters only repeat insteon signals (not X10), you do loose some of the utility.
Right now the only issue I see is a limited number of control options for insteon. They don't have the insteon equivalent of the handy X10 RF wall switches or IR to X10 converter. This isn't too much of an issue because the insteon devices can be given X10 addresses. However, because the insteon RF repeaters only repeat insteon signals (not X10), you do loose some of the utility.