The advantage is that consist of a real textbook that kids use in Spain, so what we are doing is using a native speaker book for learning Spanish language (basic level, though).
The most incredible thing is that they have incorporated audios within units, related to specific content. So, don't miss the opportunity to improve on your listening skills!
Try some audios, read some "Técnicas de trabajo" and let me know what you think!
Their website with full catalogs on books is:
Remember to stay positive, open-minded and happy help you learn, and also work in your real life!