I have two Rokus: an older Roku 3 and a brand new Roku Ultra.  I use them both to stream SlingTV.

When it comes to fast-forwarding through DVR content, they function very differently:
- Roku Ultra has a continuous fast forward at variable speeds (x2, x4, x8, etc) (depending how many time you push the right directional button), then you resume play by pushing another button.
- Roku 3 has a skip-ahead function (30 seconds for each time you push the right directional button. Ex: 6 pushes skips ahead 3 minutes, then resumes play automatically)

I absolutely LOVE the skip ahead function of the Roku 3, it is exponentially easier to navigate your recordings.
Does anybody know what is the newest model of Roku that still has the skip-ahead function?