I think it gives a different perspective in that when you have already watched the game live from the sidelines, you might go into watch the tape looking for confirmation of what you think you saw.....where as, not watching it from the sidelines is a completely different view....that's just wild ass speculation on my part.
That said, someone in the lounge said they follow UNI closely....and an assistant coach had the same experience in that he had to watch from a Hotel room as he was out recruiting or something....he came away with some suggestions for their offense that apparently can help them.
Again, not saying that it is a fact, but just know that sometimes a different perspective helps see things a little differently that MIGHT give some insight that you don't otherwise get.