In my organization AppDynamics' reputation couldn't be worse, they could never deliver on their promises even after months of consultancy, never ending back and forth with support to fix what ended up being a network issue on their side, in the case of my team they caused 2 P1 production incidents with their buggy agents. And that's without mentioning their slow UI. Wouldn't recommend this to anyone, we hacked together in a few weeks a solution with graphite/grafana that runs circles around it. Perhaps they have more value for client facing systems because otherwise I cannot understand how they are still in business.

New Relic and AppDynamics are quite similar and best in class. AppDynamics offers not only a cloud version but also on-premise installation. AppDynamics still uses Flash in parts of the UI, and the UI is more old-school but shows more data details. New Relic has a more polished UI, older parts are typical Rails pre-web 2.0 pages, newer parts are AJAX heavy modern. AppDynamics shows a map of all network components, New Relic map is quite new and more like an afterthought. Both use agents for several programming languages. All other alternatives have far worse offerings (either only good for one language, worse detail level, even bigger costs or just very outdated software) - incl two Thoma Bravo owned properties, Dell, MS, CA, etc

AppDynamics would have been one of the first SV IPO in 2017. How many SV tech IPOs will we actually see in 2017?

I've been using AppD for 2+ years, and it is better than nothing.

I have many complaints: Flash UI, data is rolled up almost immediately, use of averages, lots of capability is provided by ancient and unmaintained third party plugins. They have weird notions of compatibility (agent has to be same major version as controller) which leads to heartache when they don't migrate your SaaS controller when they said they would. Worst of all is several times the Java agent itself has been the source of a memory leak. I would expect more based on the price.

More recently, they have started trying to be all things to all people instead of being a fair-to-middling APM. Make it so I don't throw up in my mouth every time I use the UI and then we can talk.

Not the OP but I prefer New Relic's User Interface. AppDynamics has much better Java integration though. Stackify has been trying to make waves and is certainly an option for .Net

We've literally just implemented it, as in this month, and I wasn't involved in the selection process, so I can't say I have a very strong opinion yet. On first blush, it's very similar to NewRelic, with a slightly clunkier UI and a saner price tag.