Without a doubt, more people still play TDS. Even if your opinion is that TPD is a better game, the online player base is sparse at best, and in a few months will be totally non-existent. Rating in TPD is worthless, it's more like 'experience points' rather than an actual indication of how strong you are. In TDS, rating does actually mean something, and it's far far easier to get matchups against players that are similar to your skill level.