I was in the market for a portable printer two years ago, and I ended up with the Canon. The HP portable printer I looked at was not portable enough for me. It was significantly thicker and heavier than the Canon.
I recommend going to an actual store and checking out the HP in person before you buy. Some things to consider: how will you be transporting it? In a backpack on subways, or do you drive to work every day? Lots of flying? How heavy is your laptop, because presumably you'll always have the laptop when you have the printer? These types of questions can clarify how small or light you need the printer to be.