[Len Case]

Looking at the website for Daylight, I get the feeling that it is more of a personal productivity application (but I don't know since I've never used it).

OmniPlan is more for figuring out how many people you need to finish a project in time or how long will it take given the people you have. It has the standard project management features: Gantt charting, resource allocations, resource leveling (fixed resources or fixed due date), etc.