If I'd written this review shortly after installing 10.4, I'd have had more to say about Dashboard. But as time has passed, it has been activated less and less frequently.
Dashboard is a good implementation of an old technique. It sits below the application mode, so it's always there. Unlike similar solutions, you don't have to launch it manually or set it to run whenever you start up your Mac. You don't have to switch from the app your working in to another one in order to bring Widgets up on the screen. I hit F12, or click on the desktop icon and up it pops. I hit F12 again, or click the mouse away from the Widgets, and it goes away leaving me exactly where I was before invoking it.
This is the way desk accessories should work, and Apple's implementation of that is the best I've seen.
The trouble for me is that almost everything I can get from Dashboard, I can get elsewhere, and generally I'm going to do so because the information I want is in locations I'll be looking at anyway.
I always have iCal and Address Book running, so Widgets that peer into these apps' databases are useless to me. My clock is in the menu bar. Since I have to run iTunes in order to use the iTunes controller widget, I may as well just go to iTunes and select Play there. Stickies and Calculator already exist as apps, the latter also providing the functionality of the unit conversion widget. I always have Safari running, so it's as easy to open a new tab and go to Yahoo! Finance for a stock quote as use the widget.
I do use the clock widget to keep track on the time in Brisbane, Australia (family) and San Francisco (work), and the weather widget proved useful once I changed it from London, USA to London, UK. I don't look at these very often, though, because it takes Dashboard so long to get each one up and running the first time you activate it after turning your Mac on for the day.
That, and the lack of useful (to me) Widgets, limits Dashboard's utility. Other users may see it differently, and as I say, having alternative modes of operation is A GOOD THING. Unlike Spotlight, however, Dashboard is a feature you may use rather than one you will use. It's no more a reason to buy Mac OS X 10.4 than the addition of the Control Strip was to buy, IIRC, Mac OS 7.5. ®
To be continued...