Originally Posted by: GreenMoose 
*Edit: The "taking forever" part seems to be related to RS 9, it went slow with NCrunch disabled as well but when also disabling RS 9 the "speed" was increased significantly. Dunno about if crashes are due to NCrunch or RS 9 though since I had both enabled at the times.
The engine separation in NCrunch should in theory greatly limit its impact on the IDE in situations like this ... though a package install process triggers many complex activities through the IDE, NCrunch and Resharper. It wouldn't surprise me if there was some kind of cross-thread issue here.
The solution is for all of these activities to be suppressed until after the install has finished. At present I haven't yet found any hook points inside Nuget that will allow NCrunch to monitor these activities cleanly.