The contenttypes library has undergone several changes in the previous releases.
The contenttype group column has been added, as well as a column displaying the number of items of each contenttype.
And you can sort the result by clicking on the column header instead of selecting a sortorder from a dropdown. 

But those were just minor improvements.
This time, contenttype management has been redesigned almost completely. This section describes each part of contenttype management in detail.

Contenttype library

As of Smartsite 7.10, the content library looks like the screenshot shown below.

Not much difference here, except for the button bar and the fact that contenttypes which are the "parent" of a contenttype group are shown in bold now.

The main difference is the way in which the contenttypes itself are edited. In previous versions, Edit Contenttype was a single action in which you could set the properties of a contenttype (such as the name, description and the usergroups which should have access to the contenttype) as well as manage the contenttype fields and the contenttype field properties for each field.

As of Smartsite 7.10, the management of contenttype fields and contenttype field properties is no longer part of the Edit Contenttype action itself. They have been replaced with library actions, which gives a much better user experience and e.g. the option to search for a specific field or field property. It also opened up the possibility to support bulk update for contenttype field properties, as well as copy/paste support.

Another major difference is the way contenttype field properties are stored, specifically when you set a contenttype field property (ctfp) for a specific role and the only existing ctfp is set for All Roles.
Previously, the existing All Roles ctfp was "expanded" to all existing roles (for each role, a ctfp was added) and the All Roles entry was removed.

Side effect of this business rule was that when you add a new User Role, there is no fallback value for the ctfp's which are set with a role-specific value, since the All Roles ctfp value isn't there.
As of Smartsite 7.10, this business rule has been removed. The All Roles ctfp will no longer be removed when setting a role-specific ctfp, so it will always be there acting as a default value for any role.

Edit, Edit group, Properties, Group properties

Because the management of contenttype fields (for a specific contenttype) is a separate action now, there's not just a single Edit button anymore, but in fact there are four.

• Edit
  Opens the contenttype fields library for the selected contenttype. Within this library, you can manage existing fields but you can not add a contenttype field.
• Edit group
  Opens the contenttype fields library for the "parent" contenttype if the selected contenttype is a derived contenttype, otherwise the contenttype itself.
  Within this library it is also allowed to add and/or remove contenttype fields.
• Properties
  Opens the Edit Contenttype action for the selected contenttype. However, this action no longer includes the contenttype fields and field properties.
• Group properties
  Opens the Edit Contenttype group action. This action lets you set a name for a contenttype group.

Tab layout

Another new action is the Tab layout action. With this action, you can adjust/set the tab layout for a specific contenttype. The tab layout determines how the contenttype fields are distributed over one or more tabs when editing an item of that specific contenttype.

All fields

The All fields button opens the contenttype fields library. This is in fact the same library as the library which is opened when you have selected a contenttype and clicked the Edit button. However, in that case a contenttype filter is applied, whereas in this case the library is opened without contenttype filtering. Furthermore, the library will show an additional contenttype column within the result and additional filters will be available.

This library gives you an excellent overview of all the contenttype fields, but more importantly, it gives you the opportunity to set a contenttype field property on multiple fields at once (bulk mode).