I've really tried to get on with parser generators, but I've found they are hard to use, hard to debug and the languages/DSLs are clunky and weird. Except for cleanroom academic implementations, or for language designers who can afford the time and resources to learn and get good at a parser generator, I've found its better to simply use regular expressions to do matching and a functional language that can build up a data structure recursively.
Another problem is a lot of them resort to clunky code generation from the grammar file, and when something goes wrong you're not debugging the grammar per se, you are stepping through a bunch of machine generated code that you didn't write yourself. So your debug process looks like make change to grammar, regenerate parser, try parsing again, loop. etc. It replaces the entire file too, so its not like you can isolate areas of the code and work on them like you would regular code. And the time to generate the parser is often times slow.
Also when runtime parsing errors do happen, often the incorrect line/column numbers are reported, and getting good descriptive parser errors is a project in and of itself after you have your grammar written and working.