One of the really nice features of DTrace is its virtualized consumer. It means that you can run different actions for the same probes at the same time on the same system. This is really useful when many sys admins or developers are looking at the system and application. Thanks to this feature they don't have to care that someone else is doing his work at the same time. This is specially useful for scripts which are run for many hours as you can still do the other work with DTrace.