I would recommend partial bowls, particularly if you are just starting out with pipes. It can take a couple times fussing with the packing and the tamping and all that before you get an enjoyable smoke all the way to the bottom. You may get a wet, goopy, fireproof mess in the heel that just won't burn. Partial bowls ensures that doesn't happen, and I think can also help new pipers improve their technique quicker. Also, like Branzig said, something that burns easy.