The ability of having all metrics in one place, easy reporting with dashboards that can be customized according user needs/requirements! Very good support from their team when needed (we are using them since 4 years now!). There should have been more features added over time but it's understandable because they were focusing mainly developing new products at first which was not so important as people realized what could happen if you don't keep up-to date - we're doing this by ourselves nowadays :) We use vpulser mostly internally within our organization where only few users need access outside VPNs or such things like those would become an issue otherwise due security concerns etc.. It works just fine without any problems though I'd say there might still exist some minor issues here nthere depending how experienced / knowledgeable someone may consider themselves being regarding networking systems & telephony stuff ;).