The genres are too dissimilar to choose objectively, but personally I'm more likely to reach for RepCom than KotOR when I feel like playing something. But if they were to make a Star Wars RPG shooter along the lines of Mass Effect, I absolutely agree with Mia that it would be pure gold.
As to the question of KotOR-era Mandos or the more "modern"-era, I would have to go with the "modern"-era for the increased armor variety and the independent mercenary feel of the times.