I have really enjoyed using Gem, especially the particle systems but also using it to manipulate live video feeds. However, I also would like to see it streamlined so that the gemlist actually travels from top to bottom. As it is now there are a lot of weird issues where objects can be left out of a Gemlist chain but still affect it, or where things just work in ways that are counter-intuitive to how PD generally works. Certain effects like [pix_motionblur] for example will affect the Gemlist output even if their branch of the Gemlist doesn't actually get sent to a texture. For example, in the case of [pix_motionblur] I had to rig my patch to set it to zero whenever I didn't want it on, rather than simply bypass it like I do with most of the effects patches I use. This wasn't a terribly hard fix, but some of these situations are very difficult to work around, and the inconsistency is inconvenient.
I don't know any C code so I can't help figure out why this is or how to fix it, but I hope some of these problems can be smoothed out because Gem has great potential. I've used it for a few live VJ performances and really liked the results. (sorry I can't provide more specific examples, but I'm not at my home computer right now)
-Ben Baker-Smith Chicago, IL