You can't rate Dhoni as a better test captain than Jayawardene yet.
Mahela's record is amazing considering the considerably less talented team and resources he has (even taking into consideration Murali and Sanga, Mendis has only recently come to the fore) compared to other countries.
Maleha is the best captain in the world IMO. Dhoni may challenge him when we see more of him on the centre stage in test cricket. Dhoni's fields to spinners still aren't the best IMO, I thought his fields at the end of day 2 were poor and let Katich and Hussey get runs far too easily. He'll learn though, what a leader.