We are big fans of swerve as a drive-train well suited to a wide variety of FRC situations. The ability to vector drive force in any desired direction is particularly valuable. So is the independence between chassis orientation and direction of movement. Some moves are shown in the attached link:
http://www.youtube.com/watch?v=Pej5pkFvFdY
Swerve does "cost" more. We use 4 drive and 4 steering motors and the overall weight of four pivot modules is 31.6 lb (includes all motors). Also, there is a significant investment in driver training. Despite this cost, we find that the benefits that this versitile drive-train provides to us in competition makes it worthwhile.