I think it's relative... A lot of these guys were in your shoes just a few months ago, and will be able to speak on it directly.
However, here's my other essential breakdown:
In my opinion, without any prior knowledge or resources, dual lines are easier to learn (in theory) because they're linear, the fly forward under tension, it's easy to grasp.
With a little bit of basic knowledge (first-hand or via forums), I'd say the Rev is an easier kite to learn and fly, certainly to advance on.
The dual line kites require more hand speed to get really good at, and a certain degree of athleticism, whereas anyone can fly a Rev, in nearly any wind.
FYI, the avatar was made from a real photo, shot when I was doing this (another time):