The biggest title on clay is Roland Garros, not the masters1000. He has zero RG titles. The biggest title indoors is the WTF where Djokovic won it twice already. So far he has won the biggest title indoors twice. Like I said earlier, if he ends up with more WTF than RG, that will show he is better indoors. Djokovic won his WTF last year by beating the best indoors player of this generarion, Federer.
Roy, all I can say respectfully, we can agree to disagree. Nole also won Estoril and Amersfoort back in 2006 when he was only 19yo (yes they are/were smaller tournaments but still). Our disagreement might be because you are putting more weight on the WTF than masters plus other clay tournaments. Djokovic played some legendary matches on clay against the clay King Nadal etc.
as for indoor HC. the first one he won, he had it kinda easy def. Davydenko in the final (all respect to Kolya btw). The last one he won was very hard to win so kudos to Nole. However when I look at a big picture, I still think that he is more successful on clay