I'll just link you to a third party comparison, since I never used Visual Studio Load Test tool.
http://sqa.stackexchange.com/questions/9572/comparison-of-jmeter-vs-visual-studio-load-test Since JMeter don't have any built-in test data distribution component is up to you to decide what is the best approach for spreading your test data. You could use Maven and JMeter Maven Plugin or JMeter Ant Task. The goals/tasks with the distribution strategy could be defined in the pom.xml. Since you can pass parameters to maven execution, the number of machines you'll have to distribute your test data can be configurable. Any way, as JMeter is an open-source project and allows plugins to be attached to it, you can also write your own test data distribution plugin. JMeter-Plugins <http://jmeter-plugins.org> has also a plugin, Redis Data Set <http://jmeter-plugins.org/wiki/RedisDataSet/>, that can help you with this.
