Indeed very useful addition. When a hero has plenty of time left and didn’t use any insta troops plus scrolls, you know that a small improvement won’t stop that raider, even when he added you to his favorite list. When he just had 5 seconds or less left, a few upgrades can be enough to keep him away.
I would be also interested to see at which location a hero died the first time. Why? Well… When I know the location where most raiders die, I know that improvements there for towers (upgrades or forges) can make the base even more tough and could bring me more gems. It also gives me a hint where more improvements are definitely required.