I don't know that this will contribute much either but here goes...
I use the priority feature on my Palm, but not in the standard way. I use it more as an "Order of attack". Now this might not really be different than standard prioritizing, but in my mind it helps.
Each day, I go to my What's Next List (My primary action context list), and I choose 5-15 items I'd like to tackle that day. Anywhere from 1-5 of those are actual "Priority" for me, usually related to overall goals, and those get moved to a list I have named "Priority". Anything on that list is highlighted in orange on my calendar, and my rule is to try and get highlighted items completed each and every day. Usually before anything else. The color is what signifies priority.... the actual number assigned is the order I plan and/or expect to do them in.
The rest of the action items end up getting a number assigned to them, 1-5, and this number again is more about when it gets done, than what its priority is. It wouldn't be on my calendar if it wasn't important enough to get done that day. So, the item marked "1" is the first thing I do that day, then I do item "2", item "3", etc. Ticklers, reminders, and misc things end up with a "5" because they're just memory joggers or very low energy types of things.
The difference, for me at least, is that importance doesn't designate the number assigned. Item 3 on my list might be the most important thing of the day after highlighted items, but if I know I wont be ready for it till midday, or there are a couple of other things I want to do first, then I leave that at number 3 instead of putting it at 1/highest priority, where it would normally go in a prioritized system.
Not sure if this makes sense but it works for me