We've been using VisualCron for I guess about a year now. Originally we got it as a Windows Scheduled Tasks replacement. We had been having problems with myriad batch files and perl scripts were tripping over each other and over still-executing copies of themselves while accessing the database. They were causing the Task Scheduler to freeze, requiring a server reboot to free things up. Yuck!
Anyway, VisualCron allowed me to easily prevent overlapping jobs, and we have not had a single job freeze related to conflicting jobs since switching to VisualCron. We had one out-of-memory problem due to trying to access a huge debug log through the UI, but that was it.
Since then, I've expanded my use of VisualCron to include automating SQL Server jobs and adding meaningful error trapping and notification to them, as well as HTML tasks to check on the status of our web applications. I've been very pleased with all of the functionality that is present - the feature set, the general robustness, the usability of the UI.
I have also been very pleased with the responsiveness of Henrik, who I think is the owner/head developer of this program, to bug reports and feature requests. He helped us to make authenticated http requests across our proxy server, and we're currently working with him on a workflow issue when multiple DB errors are encountered in series. Responses are always prompt, dialog is active, and debug and test builds are provided in short order once there is a hypothesis regarding what the issue might be or a possible solution.
I think we made the right choice in going with VisualCron for our task automation.