We decide to purchase the solarwinds orion package about a year ago. It has been the best thing the company has ever done for the Netoworking area. It is money well spent. I use the alerting engine to watch over 40 servers. I know the what where and when something is about it happen. I would recomment this software to anyone who thinks they know what their network is doing, and prove to them they haven't got the slights clue with out solarwinds!
In my new company they had an older version of the toolset running - in a corner. I got a short introduction - and was hooked.
When we then made a major change in our network and consolidated our serverfarm i recomended to purchase Orion.
Now I can sit on my desk and keep an eye on 50 phycical and 30 virtual servers, Aprox. 200 switches and routers in 150 locations. I even get an SMS when a server goes down or is having trouble. So downtime is past - nearly!
And best of all: It didn't cost a fortune, once set up - it just performe, and I can concentrate on other things, until an alarm goes off.