I have not used iRule, but it is certainly one of the DiY solutions which is getting a lot of high praise.
Now, the real issues I have with all of this:
1. iPads aren't remotes - they work, but aren't at all convenient. Commercial comes on, you want to mute the volume, you grab the iPad (two hands, it's heavy!) and you push the volume mute button... Wait, it went to sleep... You push the power button, unlock it (what was that code again?), unless it is still running, you start the app up again. Now, you can mute the audio. If that doesn't sound convenient, then you start to understand why this type of device is not ideal.
2. Touchpanels don't work as nicely as remotes. This isn't iPad specific, but is true of all non-tactile remotes. Up/Down/Left/Right/Select... Channel up/Channel down... These are functions which you use in the dark entirely by touch. With a touchpanel every time you want to change a channel you have to look down at the panel to make the change, then look up at the TV to see if the change is taking place as expected. It is not at all the same experience as a tactile remote control. The EXCEPTION to this is in larger complex systems where you want to be able to run multiple rooms and/or setup thermostats or other complex systems.
I run Crestron in my home, which is very different, but gives me (overall) similar functionality. I have handheld remotes (URC MX-850) in each room with a television, 12-button keypads in each room that is audio only, and I have an iPad for whole house control and setup to include shades, fireplace, all A/V zones, lighting, and more.
But, when I just want to watch TV, I pick up the remote and press the FIOS button and that's all I have to do. My wife and kids have no issues at all with that simplicity - because it works.