I do it, and it really hasn't taken up all that much time. You have heaps of time to do it, so it's not like all your time gets taken up, unless you really want to do it in the minimum time. I started in year 10 (Bronze) and am about halfway through my last bit (6 months skill). I just did each bit at a time, and it's really good.
And expeditions are always fun, they are kinda like school camps except way less structured and you have to plan everything yourself, which can get a bit stressful arguing with your friends about who's bringing what, but once you've done it you have a great sense of achievement. That applies to the whole course.
I say you should do it, you can do as much or as little as you like and it is really interesting trying something new.