I am fortunate to have XM Nexrad, stormscope, and onboard radar. I have used
these in combination, including night IMC. They all provide valuable
information, and in combination give a lot of information.

In particular, the combination of Stormscope and Nexrad overlayed are
especially useful. However, up close and for use for navigating between
cells, especially at night or in IMC, nothing beats the on board radar for
real time situational awareness.