To get back on the lighting topic, I have a few more comments on Insteon that apply more to new construction than DIY retrofits. There are some good reasons why most pro installers are not using Insteon. I think they're great for the DIYer on a tight budget who only needs to control a few lights. But I'm less thrilled about whole-house control with them.
I have 130 Insteon devices and it is working OK for me.
The switches/dimmers/modules are a pain to set up if you have a lot of them. You have to hold down the button for 10 seconds, run to the other switch or controller (which might be downstairs, etc.) within 4 minutes. If you want to remove a device from the "network" it has to be "unlinked" first or else the network will slow down trying to talk to a device that no longer exists. It's a rather awkward set up if you have a house with 50 insteon devices.
PowerHome software eliminates all of these issues.
Unlike some other products, which have hardwired master and slave switches, the Insteon products are all masters and must be "soft linked" to each other. This means the electricians can't even test the other switches on 3-way and 4-way circuits when they install everything. The low voltage guys have to program them before they'll work. This also means if they become unprogrammed (see below) they stop working for even manual control.
All the electrician has to do is make sure the LED is on to confirm the switch has power. There is no value in having an electrician involved in testing multi-way configurations because the programmer might redefine switch functions from the original spec to meet a customer preference. Hard wired companion switches are always limiting because they require special wiring and once wired their functionality cannot be easily changed. Also UPB and Z-Wave companion switches tend to cost more than ICON master switches.
It's possible for homeowners (especially kids) to screw up the system. If someone holds down a light switch for 10 seconds, and then hits it again, they just unprogrammed that switch (or they could accidentally create a new link, etc.). For DIY folks this is bad enough, but at least they can hopefully figure out what happened and fix it. For a professionally installed system, however, it means a warranty callback and trip out to the house to get the lights working right again.
You actually have to hold a switch in for 10 seconds twice consecutively to put it in unprogram mode. Not that easy to do by mistake.
So, in some ways, you get what you pay for with Insteon? When the cheapest NON-HA decora paddle dimmer at Home Depot is $25, what do you expect from an automated dimmer for $20? ...
Thinner form factor, X-10 compatability, No annoying buzzing, You don't have to live in an all plastic house to accomodate RF routing...
Spending more money does get you more. Other HA switches can be centrally programmed with PC software which is far more "installer friendly" for bigger installations. They also generally have hard wired multi-way circuits that still work manually without any programming.
As noted above PowerHome handles the centralized programming and not everyone will agree that hard wired multi-way circuits are a good thing. (Except for electricians who can charge a premium for wiring them).
But, viewed another way, it's entirely possible to save a few thousand dollars (using lots of ICONs) in a whole house install between Insteon and the next closest competitor, UPB. So is that savings worth the programming hassle, replacing switches that may die, etc?
Once again, this is a non-issue with PowerHome.
The other question is which one will have more market share, support, and device options a few years from now? Will it be Insteon, UPB, Z-wave or ??? At least some controllers (i.e. ELK) can control any of them. But keep in mind your investment in the switches and dimmers is likely to be many times what you'll spend on the controller and it's labor intensive to swap out dozens of wall switches/dimmers.
I expect UPB and Z-Wave to dominate the market in the future much the way Echelon (LONworks) and CBUS do today.