Kingsindianpatzer
HOW then should OP improve?
About "Mein System": There are a lot of faulty lines, but the principles are well explained. So it is a classic book.
About Silman: It depends if you like his style. If you want to work with a modern book about Steinitz's principles take Grooten - Chess strategy for club players. It has more very well! chosen examples and teaches without repeating again and again and again the same stuff.