Yes, it's slow to load (randomly) but this is hardly a deal breaker given the overall product benefits.
However, I think what you are describing is symptomatic of the entire WHS 2011 product design, not just the Dashboard.
My feeling is that whereas WHS v1 took comparatively few dependencies on Windows Server, and was mostly a purpose-built layer sitting on top of the OS (and hence could be designed with the end user experience more at the forefront), the 2011 product is much
more depdendent on the server OS, and (as server systems are), is constructed of loosely-coupled asynchronous services that often work independently of one another. It's the nature of such a design that it isn't very deterministic, so it's hard
to make UI layers feel responsive.
In addition to addressing the current functional limitations (2Tb, drive pooling) in the product, I hope Microsoft tightens up the user experience in WHS, which will help it be a more consumer friendly product.
