Following three plots are from R

Following two plots are from ArcGis

Remaining plots are from GeoDa

Obama Kerry multivariate LiSA

Spatial Lag Scatter plots of distance vs queen contiguity

By far the easiest package to use was the GeoDa software. In addition to ease of use,  GeoDa seems to provide tools that ArcGis doesn't--in particular the multivariate feature. In terms of data exploration, GeoDa not only saved time by quickly being able to change parameters but it allowed for a very detailed and flexible way to compare changes and techniques side by side. While R certainly had the potential of being the  most flexible in that you could do just about whatever you wanted as long as one took the time to track down the functions, it lacked in what can often be the most important aspect of exploring data: visualizing in near real time and comparison. While one can do the same in R, the ease with which it can be done in GeoDa helps greatly in taking it in and grasping the big picture.

Prerequisites, aside from the obvious of knowing how to use the software, having some knowledge of what is going on behind the pixels not only allows one to 'know' what they're trying to say with the data but the possibilities and limitations of what can be said. However, after having played with spatial weights, the most important prerequisite is knowledge of ones subject. If one doesn't come with subject mater expertise and a reasonable justification of the assumptions built into the model, then its all "gobblygoop and magic".