One of the nice things about Mocha Pro is that you can run it inside After Effects, Fusion, Nuke and Flame so it is very flexible for sharing roto and tracking between a lot of users and hosts. When you you use the native tools in Fusion or AE, there is less shareable workflow aspect to consider as well.
Also to mention, almost all the companies who specialize in roto outsourcing use Silhouette, which has the most robust tool set for roto and paint.