1. Username:
Now, in Revit 2015 username will be the signed in identity. If you use the worksharing on Revit 2015 models and you are logged into the Autodesk 360 Cloud Services then the Username will be the Autodesk ID.
2.Sketchy lines:
The new Sketchy Lines feature in Revit 2015 is to apply a hand-sketched graphic style to the current view, or define the settings in a view template to apply the style to multiple views.
3. Anti-aliasing:
In earlier version of revit, anti-aliasing could be turned on and off only by using the Options Bar. Now in Revit 2015, you can choose this by views. As a result, it gives a better overall performance.
4. Sketchy Lines
Revit 2015 now has an extra sketchy line feature. In Revit 2015, each model view have this feature enabled. This can be enabled in the Graphic Display Options dialog box (see image below).
In the Graphic Display Optons dialog box, there is a sketchy lines section. In the Graphic Display Options dialog, there is a Sketchy Lines section (see image below). The sketchy lines look better if you also turn on anti-aliasing.