Your note can even be added to a case you're working on right from this window.
Tasks can use the Highrise paradigm of 'Today, Tomorrow, Next Week' for due dates, or you can specify a date and time right down to the minute.
In my tests, sync is working pretty well. I changed the names on a few contacts both in Highrise and Address Book, then added phone numbers and other data. After I performed a manual sync, everything matched up. Right now, contact images aren't synchronized due to limitations in the Highrise API that 37signals provides, but it sounds like a good handful of developers and many users are bugging the company to fix that. For the most part, most of the contact fields from Address Book seem to sync up to Highrise just fine (at least the vital ones, anyway), making Greatascent very appealing for anyone looking to bridge the gap between the portability of working online with the power and integration of the desktop.
Greatascent shows a lot of promise, even as a fresh beta, though for now it is still a beta. While synching is working pretty well for me, there is no actual status indicator or popup to let you know a sync is occurring, nor is it clear as to how often syncs are performed or if it is an instantaneous operation when you make changes. Greatascent's website also boasts integration with Mail, iCal and Safari, but those features aren't built in yet. Still, Simon Menke is doing a great job so far, as Greatascent has the potential to become one of the most impressive efforts for integrated a web service with desktop software that I've seen yet. A price for Greatascent is still to be determined, but this could easily become a must-have for any Highrising Mac user.