Hi there!
The free EA Studio allows you to use all the features – generator, optimizer, robustness tools, Historical data, etc. The thing you can not do with it is to export Expert Advisors (Robots).
But you can test it for 15 days with the free trial. You can export as many EAs as you wish. There is no limitation.
The only difference better the EA Studio license and the trial is that you can not export Portfolio EAs with the trial.