Alex,
if you already own the trademarks for Expressive, then it's a no brainer, keep it. We could go on with this debate for an age, only to find that another 'chosen' name is already owned by some company who only comes out of the woodwork when you get nearer to a launch.
exPressive sounds fine to me. I like the idea that it has vague links to printing and infers moving beyond press.
Keep it and end this debate Now.
Mark