I assume you mean: get a working iPhone app with the special cases you want to cover. It should work the way you can sell it.
My conclusion is: there is a point in your project were you need to know something on programming or on the technical platform. After you are limiting yourself to the features of the tool, and in most cases you can cover 90% of your app with that, but the last 10% drive you crazy.
What if the tools in version 1.1 has a problem with iphone 3.1, but not with 3.2 or 3.0. Probably it is caused only on devices with enabled camera and disabled wifi. How can you deal with that? At most times your tool does not give you the cahnce to learn about the error. You need to dig the logfiles and learn on a deeper level.
That being said, look very very closely at your app. Is it something which does not need custom features? Then ok, probably you have a chance. But at the point you need a single feature which is not covered from the tool (or is buggy) then you are lost. You even can't reuse the code in most cases, because the code is sometimes not available or it is unhuman and not readable.
That being said, these are technical days and if you want to produce applications you need to get into this technical world. I think these apps all promise to much and finally will end up in unhappy customers.
Probably other people have other experiences, I am eager to know.