The fact I am Ruby person myself is the only thing that keeps me hooked to MM.
And I believe, some of these speed issues in MM could be easily addressed: as I mentioned in my original message, I just don’t get it why do we want to regenerate every single page if I make the change to only one file.
When we build our sites, we don’t introduce the changes to ALL the files, usually we only add new or modify few of the existing files (add new or modify existing articles). The issue lies in modifications to few files that still forces us to regenerate entire site.
IDEA: Upon executing the build, Middleman would look up which files were modified since the last build (snapshot) and only regenerate those which were changed.
This alone would be a HUGE improvement and it seems fairly easy to implement without a need of rewriting the entire core from the ground up, maybe even as a gem before it gets merged with the core project.