Upgrading from 618?
I bought a HP Photosmart 618 a couple years ago. It started having trouble almost immediately but I was able to fix it the first couple times. Unfortunately, it's now both defunct and out of warranty. HP offered me a trade-in deal, with the choice of the 720, 812, or 850. Are any of these models worth shelling out the money, or should I avoid HP, given my earlier problems?