I recently tested 4 apps I found on MacUpdate for less than 20 minutes each. I feel that should be enough time to figure out if this is a usable product or not. Of the four tested, MyTime was my personal winner. The interface is simple, intuitive (I had a client, project, and flat rate set up, then exported invoice to HTML template in less than 5 minutes of opening the app), quick, free of bugs, and not very expensive. I would recommend this to freelancers like myself who just need to keep track of time/projects and remember to get paid for all those projects.
Other apps tested:
TimeLog - more than I needed
TaskTime4 - too many windows
GnattPV - I don't need charts
I think the best feature for me is to be able to create my own HTML template for invoices where I can just export the data from MyTime. In the past I have created invoices by hand in Illustrator, then save as PDF and send to the client. Now all I have to do is export to my template, print to PDF, and send email. All of which I can do with some Automator scripts. Thanks MyTime! I'll be purchasing before the trial period is over.