Illustrate was one of my favorite Suiroza mechanics to come out of this project so far. It does present us with a lot of problems, not all of which I'm convinced are surmountable, but I think of the exemplar family of mechanic designs, it had the most going for it - it was unique, memorable, fit nicely in both the {W}{U} color pie and Suiroza's creative vision.
However, it doesn't mesh too well with NWO (both in terms of mechanical and board complexity), it is very hard to create interesting cards that are useful as an aura that don't become bah-roken once they're global bonuses, and finally, the mechanic sits on auras, with all the baggage that comes with it - two-for-one removal, dead cards if you don't have an enchantable creature, etc.