We have been using iCIMS for our business since 2009. During that time, we have seen iCIMS continuously improve the features and functionality based upon direct customer input and feedback. Their supoport group is strong and the training portal and API support options are the best I have ever seen in an application of this nature. The ease of use allows for quick ramp up times and transition to productivity for new recruiters.
I would highly recommend iCIMS to anyone considering a truly robust Applicant Tracking solution.