I have a couple of Roku 2s (model 2720) connected to TVs which get infrequent use. I’m having troubles streaming live TV to them. Almost everything I watch buffers almost constantly. Both worked fine when I first connected them but as time has gone by they’ve become almost unusable. Both are connected via wireless to an N router. Wireless signal for both is good. Max recording quality is set to 8 Mbps. Streaming of recorded content is good.
I also have a Roku 3 connected in the same way and have no issues with buffering.
The only thing I know is that the original 3rd gen Roku, Roku 2 was pretty underpowered processor wise. I used to use a 2nd gen Roku XD… maybe I’ll hook that back up and see how it does. It too would be considered “underpowered” nowadays (should be slower I think than your Roku 2).
What recording setting do you use? I use the recommended setting.
I’m using 8 Mbps, which works great (and looks great) on the Roku 3. It’s the one which is used the most.
Any ‘numbered’ Roku is now at least two generations old.
As @cjcox points out, they are quite underpowered processor-wise, but it could also be how far away they are from your router.
A good test would be moving one of the Roku 2s to the location of your Roku 3 that works well.
If it works OK, then it’s a WiFi problem. If it works just as shoddily, then it may be time to upgrade.