There are a few plugins which can assist you in building your CPT's, and these can usually handle your taxonomies and sometimes postmeta also. Some even take it further than that. I know that as with any plugin it's possible that development may cease; but aside from that are there any reasons why it's better to code your own CPT's taxonomies etc.
Here are some of the plugins I'm referring to
- Custom Post Type UI
- Types
- WCK
- Custom Post Type Maker
Here's my Advantage/Disadvantage list
Advantages
- Quicker and Easier
- Developers have hopefully considered security so no need to worry about nonces or protecting the database etc
Disadvantages
- Might be a performance issue for some applications
- Depending on development to continue.
- Possibly Less Flexible
Does anyone want to add to or take away from this list?