Plasma transport and energy dissipation in the driven dynamic magnetosphere are intermittent (bursty), and occur on a range of spatiotemporal scales. System observables such as geomagnetic indices, and auroral images, show evidence of scaling in the statistics of these events. Taken together these are hallmarks of a complex system. Here we underline the importance of robustness in these statistical signatures with respect to variability in the drive, and of bursty transport as opposed to intermittent structures, as key signatures of nonlinear complex avalanching systems. Power law statistics of bursty events do not necessarily require an underlying nonlinearity.