The widgets refresh when you're active on the screen that they're present on. So yes the system resources will be used more if you're main home screen is overpopulated. But they don't use too much of the resources, so you'll see minimal difference if you switch things round.

 

What about the HTC weather widget? On my (stock) Hero, it often stays several hours behind, even though I play with the phone.

 

When you go onto the screen which has the weather widget on, and stay there for a couple seconds it should update. Until you're on that screen for a couple seconds it will stay on the previously collected data.

It's the same with the clock widget that comes as a default home screen when your first get the phone. If you unlock the phone and check the time straight away, you will notice that it doesn't show the correct time for a couple of seconds, it probably shows the time that you were last on that home screen.

From my experience, the same scenario occurs for all widgets.

 

The weather widget is different, as in you actually set the intervals with which it should check for new weather

 

Really? Where? All I can see is a "Update automatically" checkbox in the weather app settings, nothing else. And it often stays several hours in the past. Not the widget, but the weather app itself - the update time on the bottom of the weather app screen remains in the past. Therefore I sometimes get awkward situations with the weather app stubbornly showing a full moon at sunny morning at 11am, even after several minutes of phone awake time.

There is a 3rd party weather app containing widget set with ability to set update frequency, but I didn't like it - its theme looked a bit weird, and the location text alignment was always running off to side of the widget with longer strings.

 

what i do is i keep the mobile internet turned off when not using i can easily have 80t70o percent batt left around 3pm starting my day at 6:30

 

It looks this was added between 1.5 and 2.1, as I don't see it there - only update/don't update checkbox.

Great, now I have one more reason to look forward to 2.x update.