I use EF database first in order to provide more flexibility and control over the database configuration.
EF code first and model first seemed cool at first, and provides database independence, however in doing this it does not allow you to specify what I consider very basic and common database configuration information. For example table indexes, security metadata, or have a primary key containing more than one column. I find I want to use these and other common database features and therefore have to do some database configuration directly anyway.
I find the default POCO classes generated during DB first are very clean, however lack the very useful data annotation attributes, or mappings to stored procedures. I used the T4 templates to overcome some of these limitations. T4 templates are awesome, especially when combined with your own metadata and partial classes.
Model first seems to have lots of potential, but is giving me lots of bugs during complex database schema refactoring. Not sure why.
