Go figure?? I'm guess one includes data logging with dash while the other is just the dash? Write-up is confusing.
Just an FYI on the IQ3, I updated the firmware so it now supports >2GB MicroSD cards -- I have a 4GB MicroSD card in it -- probably overkill but memory is dirt cheap. Also, the USM (Universal Module) is definitely the bargain way to go if you want to use existing stock sensors -- basically supports 4 sensors in one module $180. And the USM sensor support is very very good, from digital to analog to all types signals. But the IQ3 Vnet sensors are IMHO, pretty over priced $250 just for the boost sensor?! Now if I can just find a "failure prediction" sensor