I was previously using ESC , an open source HA application, and I must say that this is just as powerful, costs less, and comes with all the hardware needed to run it. Replacing a PLM was just a dumb idea before the ISY. I have approximately 60 devices with four separate breaker panels, detached shop, sprinkler, HVAC, security, and working on adding surveillance.
We had a massive power surge, destroying 80% of the controls and I seriously dreaded the operation due to the size and complexity. I thought about abandoning it and just going back to an "IQ Challenged" home but instead decided to check out the ISY because it looked like it would greatly simplify the installation. In about an hour, not including controller install, I had it up and running complete with links and scenes. The programming I did in bits and pieces in my spare time and will never be complete since I enjoy finding new applications for it. I have integrated my Android with a couple of other apps with the ISY, for instance, I have a Koi pond and I was always forgetting to turn the skimmer back on when I would feed my fish. So now when I am heading to grab the fish food, I jiggle my phone and say "It's time to feed the fish" my phone activates a scene on my ISY that turns off the skimmer and sets a timer to turn it back on once the fish are done eating. I can never forget to turn the skimmer back on.
The ISY has simplified the structuring of my HA network so much it is ridiculously easy to install. Once surveillance project is complete I will be integrating my home theater as well. After that drapery and window controls. I hate the scramble in the spring when the windows are open and it starts to pour down rain. We have casement windows, the crank type. I plan to add motors to the windows that will be controlled by the ISY which will detect precip and close them automatically and then turn the AC back on. Then I can also program it to monitor outside temperatures to trigger AC/Heat on/off and to open/close the windows, if it's not raining, or shades to save on heating and cooling costs. I am knocked over by how simple that will be to program. It will simply consist of some mouse clicks and DONE!
The potential is limited only by your imagination. If it is powered by electricity, AC or DC, it can be controlled by the ISY.