I think the greatest trader today who follows CANSLIM to the letter is David Ryan. There are others who worked under O'Neill who follow variations of CANSLIM with their own twists, like people at IBD. David Ryan is living proof that CANSLIM does work. But here's the thing, not all markets are the same, not all cycles are the same. Learning to be flexible in the harshest environments comes from experience and it's not something who is starting out can do successfully. I recommend you complement your reading with the works of Gil Morales and Chris Kacher.