Wow. 5 minutes feels like an eternity on the web :) I feel your pain.
The speed of the app depends on several factors, most important being your computer speed and browser.
You mentioned you’re using a Mac. We test on a Macbook Pro (OS 10.5.8, 2Gz Processor, 2GB RAM) here and CalendarBudget runs very fast (takes just seconds to do anything).
Are you using the latest version of Safari (5.0) or Firefox (3.6)? If not, upgrade to the latest version which should improve the speed a lot. In fact, the fastest browser we’ve tested is Google Chrome, which now has a Mac version. Give it a try at http://www.google.com/chrome?platform=mac.
CalendarBudget flies on Chrome!!