Electronic PCRS

I have a question; We are a small agency that does on an average of 800 calls a year. We are looking to bring our agency up to modern times and go to electronic PCRs. We are looking into these three companies:
EmsCharts
Zoll Epcrs
Eso Solutions

Does anyone have any idea, what the Pros and Cons are to each of these or preference as to which one is better? Thanks. Keith