On the fire tv you hit the arrow buttons and it skips ten seconds at a time. Can que up as many as you want.
On the Roku it skips ahead also, but it doesn't tell you how far it's skipping and you have to hit play every time because it pauses afterwards.
Wow! That is a pain! I can see why you wouldn't bother. Unfortunately for me, after doing a bit of research, the Roku offers apps that Fire TV still doesn't (e.g., College Sports Live). I have until football season starts to pull the trigger on a device that will also enable me to stream my favorite college team's games directly to TV (without "casting" or hooking up a laptop or tablet).