PBL and Rubrics

What about PBL and tech? I've long been a proponent of good PBL (project based learning). I've come to realize a few things about choice and assessment. First, regarding choice. we have to give the students real freedom of choice in design and execution of a project. Better yet, we should give multiple choices of projects for students to choose from so they feel and have real control in their education. This, of course, naturally relates to assessment. I'm a fan of rubrics- however, with rubrics we run the risk of a tyranny of the checkbox, in which the students simply views the project as little more than checking boxes. What if a project is brilliant but doesn't fulfill all of the requirements? Is that a flaw of the project or are we guilty of making all students jump through the same hoops. My rubrics have become very open ended. 
Backwards by Design type thinking helps one create good open ended rubrics. Yet, even BbD, IMHO, can be limiting if we let it. For suppose a student takes a seed of idea germinated in class and produces an outcome different from what I even considered? Rubrics are helpful and good and far better than grades alone. I've learned, especially when students are using technology, to be careful about how I create my rubrics. I don't want them be limiting. I like the rubric below, but I find parts limiting. Suppose a student doesn't want to use color, for instance? In a different vein, rubrics can cause trouble because the ostensibly suggest objectivity- a series of things that one must produce. But in the rubric below, how does a teacher define "unique" in creativity? Rubrics, if misused, can imply a objectivity that does not exist.