I have a couple different versions of the keybord you linked too, search "Ipazzport" on eBay.
http://www.ebay.com/sch/i.html?_nkw=IpazzportThose are cool and I use one to control my main PC/TV which is an ArcadeVGA (15 khz) equipped PC attached to a sweet Sony PVM monitor.
The niche that the the iControlPad2 has is gaming controls (dpad, buttons, analogs) built in with the keyboard.
Personally it is not for me as I don't have a tablet or a smartphone that needs physical controls.
As an owner of a Pandora
http://www.openpandora.org/, made by some of the same people, I appreciate having the controls and keyboard on a portable device.
Great for general computing, game console emulation, and computer emulation.
For home use I have the aforementioned iPazzport and four original Logitech Cordless Rumblepads.