Like many people I've tried to learn another language, in my case Dutch but didn't keep it up, in part due to the style of teaching used by my chosen 'popular' learning course.
What I like about Rocket is that everything is based around conversations which at whatever level you reach is crucial. I also like the multiple testing methods which hopefully will make things stick permanently! Finally the inclusion of the cultural pointers is very good and I'm sure it's a big part of your completeness as a speaker of your chosen language.