What sets Yookoso! apart is the grammar explanations. They're academic and brief to the point of being a little unclear. But there are a lot of example sentences, tables, and other material to flesh out target concepts. It's like Yookoso! quickly explains how to swim then pushes you into the pool.
This focus on example sentences is a great way to get a feel for Japanese in its native habitat and will give you a strong collocation background. Though short, the grammar explanations do a fine job of teaching you the nuts and bolts of the language, breaking down the rules so the example sentences do you a lot of good.
And while Yookoso! teaches a lot, some may find its content outdated and hard to navigate. The first book in the series begins with a bootcamp of sorts that can disenfranchise beginner learners. It seems like Yookoso! was meant to act more as a college classroom textbook rather than a self-learner resource.