The eternal question: which heroes are better, mages or warriors?

I voted for the Warriors. When I was first learning to play, I was told that mages were the best and that I should only play as them. Later, I met some players who played as mages, and they started telling me how they play and what they do. Well, I thought I was already a pro in Heroes, so I played as some mage against Tazar – and I lost badly, to put it mildly, and had to start learning again. But that's just a story. Recently, I started playing again and decided to see how the pros play. I went to YouTube, found a bunch of videos, and noticed that if someone gets a hero like Shakti, they always make him their main hero. So, the question is: what's so special about him? Why, even though he has Crag Hack, does he still choose Shakti?