I've been playing with Ragel all day - its so interesting, and actually not that difficult to get started, even though the concepts are fairly abstract.
Its also nice that the software is pretty robust. The problems I've run into include endless loops or syntax errors, but not much other than that. I'm a little nervous that the code I'm writing for use with ragel is total spaghetti, but the task I'm focusing on isn't incredibly complicated (a Markdown parser and transformer), so even if it is spaghetti, it won't be too tough to disentangle.
I've added a bunch of notes here on the Ragel page of the Docunext wiki.