Well, this isn't a full out review of the inkling, because I've only had it a few days. I had some trouble exporting from it on my old version of Adobe Suite, but I have CS4 at my office, and that seems to be working fine.
Here is a cartoon sketch using the inkling.
He's my evil Santa Claus. I am still playing around with some exports from Illustrator. I'm hoping to take him home and color him in Gimp. More Santa Claus editing later. I still think this turned out pretty neat. When used on the right paper, the inkling does nice sketches.
I used it on trace paper today at work. It wasn't as pleasant of a sketching experience. Here are a few shots from today:
Overall, I'm happy with the pen so far. I'm thinking it will be more useful for cartoon and blog sketches, but I could see it coming in handy at work as well. It's definitely an easy way to get quick, casual presentation drawings out.