Err,
not sure what question you're asking here!
IMC rating is very useful for progressing onto the Instrument Rating, which you must have for ATPL issue. It provides a decent insight into what the IR's about, and it'll save you time and money (approved or Non-approved) when it comes to doing the course.
If you're actually asking about whether the IMC is useful for getting yourself out of the ****, then I'd say.....maybe! Thing with IF stuff is that you need to keep in practice with it.
To summarise - crack on with VFR Nav if you wish to hone these skills for the CPL skills test (Nav is harder than PPL level), otherwise, I'd recommend doing the IMC for all the benefits listed above..........