I enjoyed this. I'm generally not keen on spoken word or contemporary performance poetry. I find the idea of competitive arts in Slam poetry contrived (I also find poetry competitions pointless), the stuff people write for local readings usually seems either lazy or overly egocentric and the reading themselves more like fashion shows than a sharing of work. It just tires me out.
It's interesting what you say about restrictiveness. If only the restrictions were based on some kind of transparent and thought-out manifesto rather than on timing and technology.
I recently got my poetry writing students at UWS to do a reading of work they'd produced over the semester, with a view to getting them to write poems that are both publishable and performable (like the Beats did). This forced them to really do the work, think about form and structure as well as voice and sound technique. It was a success, great energy, some really solid work from first-time poets.