I use it both at home and on my previous job at a big datacenter with several hundreds of monitored devices. Worked very well and the map is superb. I haven't seen anything comparable. Espacially the realtime traffic status of network links (witch fade to red when overloaded) is a grad diagnostic tool.

They should take a look a the spam filters at yahoo mail. I have an account there for over two years,that I give to people or websites I don't trust and I have not received a single spam-mail on that account.