NewRelic replacement?

I am currently using NewRelic for a Rails production project, around 5 EC2
servers, and the pricing for a non-free account is extremely bad (personal
opinion) while of course the free account is no good since the data only
sticks around for 1 day.

Does anyone have any experience with any alternatives to NewRelic that they
used in a production environment successfully?

After doing research on the topic I found many alternatives and a strong
contender, but I would like to get some opinions for someone that I know
for sure (hopefully) used the service themselves.

Cheers.

Have a look at zabbix.

I currently use appsignal, happy enough with that. It can also be
worth talking to newrelic - when we last used them the deal they put
us on was a fraction of what the publicly advertised price was.

Fred