Here they are:
There is no impersonation step
This is somewhat understandable. Impersonation step in unreliable because when the employee who deployed the workflow leaves the company and the AD user is removed, the workflow will fail to start.
Cannot set permission on items
There is no way to replace permission on items. This was very useful in some cases.
Lookup Field - Additional Fields
Consider having a Lookup field linked to another list that is retrieving some additional columns. For example the Title is the main column, and you also retrieve the ID and Status fields. In 2010 you can work with these additional columns, but in 2013 only the main Lookup column is showing up.
In 2010 Workflow:
In 2013 Workflow:
This is crazy. Yes, you could retrieve the ID as the main column instead, then do a Lookup on the other list in the workflow. But in this case the New Item form shows a dropdown with some numbers instead the lookup field of your choice. Here you can use InfoPath to customize - which is retiring.
There is no Else-If
Even the Else branch is missing from the auto-complete.
Wait for field to not equal a value
In 2010 Workflow you have all the options:
In 2013 Workflow there is only the Equal:
Start List/Site Workflow
Via a 2013 WF you can only start a v2010 workflow. Wtf??
That's it for now... I'll update this post once I find some more annoyances.