Really interesting subject to treat ,so here you have my point of view.....
Indeed when I started Learning English ,OI focused on Grammar basics ,that time I couldn't read and undestand every word ,after about 3 years I bought some novels of Oxford which has realllllly helps me to read and talk English, since they were bought with CDs ,so i take the novel read it well ,than when I am doing my home works I listen to the CD, !!!
it's realllllllllllyyy useful ! it developped my skills very very very much!
Hope the same for you !! Goood luck