we have the caddy that is (I think) from the year before they started putting the basket underneath. I liked it OK, but we just bought a Maclaren Triumph and it is WORLDs better. We still have the Caddy, so i can make a side by side comparison --
-the caddy is MUCH less comfortable to push. the handles are not padded (don't know if they are on the newer model) and they are at just the wrong height. you can also push the maclaren w/one hand, and you could never do that w/the caddy. it also has handles that are shaped more ergonomically and are padded.
-the caddy is less comfy to sit in. the edge of the seat (where little legs rub against) is not as padded as the Maclaren
-the caddy is not as easy to fold up. I LOVE the way the maclaren folds. the chicco is tricky (unless they have changed this, too) and at times i have almost had to put it in the back of our SUV w/out folding it up b/c i got so frustrated!
i know the Maclaren is more expensive, but we were able to buy a 2005 model at just over 100 online (w/free shipping and no tax). i really thought it was worth the price difference.
go try both out at Babies R Us or Toys R Us...then buy whichever one online...
EDIT:
OOPS!! JUst read that you already bought the caddy. you got a great price for it! nothing major wrong w/it, it's just once you've tried the maclaren, you can't go back!

also, your kids are older, so you probably have less need for one than we do (we have a 3 1/2 yr old and a 16 month old).