We were using New Relic, but it wasn't providing us the info we wanted and it was so expensive that we couldn't afford having it on all production servers. I've been using Stackify in a .net, Azure based webapp; the app is with high traffic subscription service, and solid services is essential. In one case we were using Stackify to identify an issue that made the site slow occasionally; it was very hard to pin point the source of the problem. Once installed it was a very fast process and we identified the combination of issues that lead to this behavior. Having the log and error data as part of the detailed trace was tremendous help. And seeing all the logs recorded when an exception was thrown is a cool little feature. Personally I can watch their real-time tailing all day long.