If you plant dwarfs, pay close attention to how deep you set them. The "union" where the tree was grafted onto the rootstock must be set above ground level. If it is under the dirt, roots will sprout from this area and you will lose the advantage of the particular rootstock the tree was fashioned from. It's pretty obvious, as it makes a bulge where the trunk and rootstock come together.
Speaking from my personal experiences, I have planted my last dwarf fruit tree. I find them highly susceptible to various diseases and fungi.... more so than standard fruit trees.
