I'll preface this by saying I have never used Soap UI seriously until the past month, in the past I have done one off tests for a new web service app but never spent a lot of time with it.
Now I'm using the open source version of Soap UI to test web service calls in our environment, functionally the tests work well and we get a very quick result as to whether the service calls work by using assertions to validate the responses. That part works fine and I believe I have a handle on that. We're still learning how to get the most out of Soap UI and have generated some Load Tests that we run from time to time. What I notice most is that often the number of requests and the average time for responses varies from run to run, this can happen even if the runs are done one after another. Reading through most of the Soap UI documents on Load Testing on their site, they go over how to set up and run tests, but little on comparing results or getting a long term view of performance using the tool.
If I have a results export, is there an optimal way I can use this data to get an overview of how well we are doing or is the best method to do the graph while the test runs? Not comparing test runs seems contrary to the whole use of reporting to me. Or is there another method that will give me a better overview of performance and give me an idea as to how good, or bad, we are doing over time? If the answer is Load UI will do this that is fine if someone has some corroborating evidence, I just haven't found that as a solution yet, although I doubt we'd buy the tool just for Load UI.