Haven't done such yet, well at least not to such a level. It's hard to get time to do more than the basic studies of vocab/grammar before even touching immersion. Really daft though because to really use a language you have to listen to it at the very least. I've been set back somewhat the past while, but once I find sense of stability, I'll find my footing again I figure.
You help motivate me to doing more though, so cheers!