I spent a bit of time in Pixelmator today cleaning up the template document. I think that the template was a good idea, as it allows one to do GUI layout very rapidly. Each component is now grouped, making it easier to move around and position relative to other components. I also added an alignment layer for each component, so one can quickly do pixel-perfect positioning from Introjucer.
The result of this work was redoing the demo app for TeragonGuiComponents and doing a new GUI for HiLoFilter. I decided to redo the demo app GUI because when working on the template document, I noticed that label opacity and component positioning were incorrect. The original GUI for HiLoFilter was made without the template document, and it was actually faster to redo it using the template then it would be to retrofit it with the alignment guides.
It took me some time to get HiLoFilter compiling again, it seems that every time I open up a plug-in, I run into problems with some library or another not compiling under whatever the latest version of Mac OS X is. However, it is fruitless to simply curse Apple, instead one must fix the errors and raise the minimum supported OS version. This means that when all of the plug-ins have been updated with their shiny new GUIs, the minimum required Mac OS version will be OS X 10.7 (Lion).
I personally wish that I could still support Snow Leopard, however Apple is making it increasingly difficult for users to lag behind on older versions of Mac OS, which I suppose isn't such a bad thing. However, I personally haven't made the upgrade to Mavericks myself, as I'm still waiting for many plug-ins and sequencers (namely Ableton Live) to be supported. It's a bit of a Catch-22 situation.
On the plus side, I will be able to ship the 64-bit versions of all plug-ins, thus ensuring that they will be compatible with the latest version of Logic Pro X.