I’d say that while I do a lot of my study here at LingQ, I also use other resources. I believe that , unlike Mark suggests - although I understand his bias haha - it’s good to do other things too. (Even Steve himself doesn’t do 100% on LingQ). But, I’d never, ever do Rocket Spanish… 
Talturios - Madrigal’s Magical Key To Spanish - awesome book. The series is really great.