As an observer, every cheatfeed solution I have used required me to keep track of two screens at the same time, which is not optimal because observing TF2 requires you to pay close attention of what happening in fights. If you want to observe well, you have to make split-second decisions on who to observe in team fights, otherwise you will miss important parts of the fight (that don't show up on the cheatfeed). With the cheatfeed, you may be able to show more big plays, but the game overall will become harder to follow for the viewer because the observer is distracted.
The best solution to this problem is the approach we had in RCADIA, which is that the technical director just keeps an eye on the cheatfeed and tells the observer if something big is coming up. That way the observer is fully focused on the game but can still capture all the big plays. However, this requires two people to pull off, so obviously it's not feasible for online production for the most part.