Congrats Bob,
I was never a Laptop-guy myself (anything that I can't upgrade myself is out of the question for me...
) but I think the advantages over the UMPC are the same as my newest Mobile Phone (a Fujitsu-Siemens T830) over most of the other Omni-Phones out there.
Small size may be cool, but you need to be able to actually use the device, and the more functions it has the more keys it should have (really..) because all those fancy on-screen keyboards and stuff just don't have what it takes to replace a REAL keyboard and systems like predictive input have their limits...and you usually find them more limiting than you would expect...
I love the T830 because it means I can enter text (for calender entries, mobileread.com posts on-the-go and short emails) easily in whichever language I choose and can also tap the screen to quickly select certain links in the browser and so on...it's the first gadget-device where I have the feeling that I can actually use many of the functions...!!!
I hope you are as happy with your device as I am with mine!