Currently use QC to make custom layers for Bonix TV - a vision mixing kind of application for OS X with a kind of QC stack of layers, each layer being a composition with published ports and some protocols for data types. Also generate sports graphics and twitter feeds and so on for video score boards at large sporting venues.
Spent a few years learning Quartz Composer as my way back into coding from a decade away doing design related work. Film, graphics, studied Architecture for a few years and got involved in publishing then film. Now moving into front side web development. Hope to get into app dev with Vuo and rapid app prototyping.
But having programatic changing of input lists and ranges is something I'm really wanting was a constant source of frustration with QC for me, so I ended up making HTML?CSS/JS interface for one client doing livestreams at stadium venues.
I just spent several hours over a couple of days trying to program something in After Effects using expressions to create a paramedic text quote FX and it was pretty nightmarish just because the UI is not set up for coders. took about 20-40 different expressions, possibly a JS script writing the expressions into the file is the way to go but I haven't gone that far yet. Any how I hated the experience, as I could have made something in QC to do same WAY more easily and wish I had have gone that route and bought the NI wrapper software to make it PremPro/AE compatible. So really interested in a beta of this, and the other FR for the Adobe apps (bigger market than FCPX/motion if you include Windows machines).
HTML page link looks good, there was a plugin for QC (not the Kineme server/client plugin) that created a web socket which allowed pretty effortless UI construction in a browser window, I loved it, sliders you can set the range of and sliders and menu items that are dynamic i.e. can be changed with code, depending on the context/state of code.