Wasy-to-use interface, where I can see all the recorded requests on left and where it is easy to witch beteen them.
Also, on the right I can access and adjust the details of each request.
The clear view of screen shots also is helpful.
The automated correlations and parametrazation is very solid.
It tend to become somewhat expensive for commercial use. Maybe raise up the limits for free edition could bring more users of NeoLoad!
Im using it to performe tests include load, spike, smoke and other tests. So we can make sure that our website can handle unexpected load in a peak days pr hours like holidays situations.
Also its easy to use and its customer support make wasting to much time is rare event.