| Custom sites | STP files |
|---|---|
| aspx pages and webparts are upgradeable | upgrade possible only for webparts |
| manual editing of xml files (onet.xml, schema.xml) more control, more work, e.g. views must in lists must be created in xml. |
quicker development (WYSIWYG in SharePoint) |
| no direct SharePoint designer development | forms can be modified via SPD |
| one template for all languages | one template for each language |
| easier deployment – one wsp file for the project is created and deployed automatically with every build | solution must be created manually with postbuild.bat and wspbuilder |
| actions can be easily added when provisioning custom site | features must be activated manually |
| Custom lists can be be extended through ECB extensions | connections between webparts can be easily created |
Currently known problems with Custom site development
1. Cannot bind RowProvider, RowConsumer and simillar webparts programmatically, it is possible only in UI.
2. Cannot create a custom list based on document library type an error occurs.
One can upgrade from STP to Custom Site definition with SharePoint Solution Generator, but there are some limitations see this.
Vojtech Nadvornik's Blog 