When it comes to Performance Testing, there are a huge number of tools out there.
We've had feedback from our partner agencies that JMeter is the skill that is in the most demand from the market place which is why we run the course, however that's not a reason for you to adopt it. Below we will take a look at some of the alternatives.
JMeter is open source, so there are paid options like HPE LoadRunner that can be better depending on how you'll be using it. If you're testing a web (browser-based) application, then JMeter will be fine - it handles RESTful interfaces brilliantly. HPE LoadRunner supports many more rare protocols and also integrates with other HP Enterprise test tools. HPE LoadRunner also comes with support, which can be handy if your application is using difficult network protocols to communicate. Support is costly though and has mixed feedback.
When doing a comparison, you also need to consider that simulating a huge number of users needs a lot of computer power. If you use a tool that is not well known, you'll have to build up your own server stack to support the tool. If you're using JMeter, there's a lot of cloud-based infrastructure you can upload your scripts to and they provide the firepower, e.g. BlazeMeter or Flood.
Which means that you only pay for the power when you need it. Brilliant.
Running 'Performance as a Service' allows you to run your thousands of users in the cloud and then turn them off at the end of the test. That's the beauty of cloud power. BlazeMeter also offer great JMeter support and much better reporting functionality that the JMeter tool offers on its own.
The cost of using these cloud-based systems (or supporting the server needs in-house) needs to be factored into any tool comparison. Most of these cloud-based performance infrastructures seem to accept JMeter scripts, so it would give you a broad choice of tools out there. I'm sure paid options like HP LoadRunner will have their own dedicated cloud-based options also.
In terms of other open-source options, Gatling is very well thought of in the industry and seems to be on a par with Jmeter. There's a good comparison between the two on OctoPerf's blog that is well worth a read.
Good luck and happy testing!