When I was an early adopter of Joomla 1.5, I immediately sought a solution that worked with the upgraded platform and tried a few other extensions. I was relieved when the folks at Joomlatools.eu developed an update, and when they moved to a subscription model, I gladly paid the inexpensive price, and their update/development progress has been on the cutting-edge ever since.
The beauty of this extension is how deeply it can be customized with its fine-grained permissions system, but despite its wealth of features, retains an intuitive and elegant interface.
Finally, the developers have a great sense of customer service when answering questions promptly and cheerfully.
In short, a highly recommended extension. My favorite for Joomla!