I used Pimsleur to learn grammar. By the time I'm finished with Pimsleur Japanese IV, I end up at around JLPT4 and JLPT3. I heard that by the time you finish Genki 2, you would be somewhere around JLPT4.
What Pimsleur does is it enables you form a sentence based on your intuition of how a sentence structure is made.
What I don't like about textbook approach is when the textbook doesn't have a workbook that demands you to form sentences based on the grammar points that you learn, simply you are to recognize what a sensible sentence is.
Recognising is far far simpler than constructing.
So a workaround is formulate your own exercises, but I feel another problem is when those sentences are formed ONLY right after you've learned the grammar points.
A bit like, form a sentence, take a look at the lessons learned today, done.
Well, one workaround is to continue practicing formulating the same or similar sentences with SRS and you can freely do that using Anki.
Similar approach to SRS seems to be used by renshuu.org but I don't subscribe to the site as a premium user so I don't know what it has to offer.
Think about it, though. I spent 1 hour every day for 120 days flat and the only reason why I can't understand this or that is because those grammar points have never been taught in the lessons.