How to add Custom Post types WITH custom input fields on the EDIT form?

OK, well, the last thread I started on this subject seems to have gone dead.

I am very surprised how hard this is to accomplish. What am I missing? I am shooting for something like this:

https://blog.genuineinteractive.com/post/adding-custom-field-gui-to-custom-post-types-wordpress-3.aspx

Except that this example does not work for my 3.01 installation of WP. I’ve got all his code in my fuctions.php, but the edit page for the test post type still shows a simple edit page with the Custom Fields section at the bottom.
I can’t find an examples of how to do this anywhere that works. Il need to be able to add customized meta fields that are user friendly. By that I mean they have plain language Labels that are static (not simple custom fields that are open ended) and input fields that are constrained like those in the example above.

Also, I am very curious what the usefulness of having a custom post type with custom fields that are only fill-able through code?? That’s what most people are talking about out there. Sure, I can see some cases where that would make sense. If we have a very basic task that we manage all through code, but what about a custom post type that we want to the User to enter actual data for? Doesn’t it seem obvious that we want them to have a guided, controlled input form? Please help. What am I missing here?

Thanks
Rich