Assassin's Creed Revelations can frustrating, but is overall worth the time. Focus on making money, and farming the templar dens for apprentice's xp. The guides are getting better, if you get stuck. Relaying on R1 Square(s) with a few kicks will solve most combat situations, will your assassins can take down anything. You can fight off 20 or 30 elites with blocking and spamming Square. You can also work around the den defense with a level 15 assassin if need be.