When I used User Agent Rules and select another theme for iphone (for example), changes are done in CSS only, but I want to change content and layout too.
The User Agent Rule only changes the theme but the store view remains the same.
To achieve what you want, you have 2 possibilities. Both of them require you create a new store view for
First solution is to assign a different subdomain for the new store view, like
m.domain.com, and on
.htaccess level redirect the users to the correct store view based on user agent (see here)
The second solution is to filter the user agent in
index.php and for each set, load the correct store view. This way you can keep both store views on the same domain