The National Hockey League's trade deadline this year was one of the craziest I can remember in recent years, not because of the players who were dealt, but the cost that had to be paid to add even a bottom 6 forward to your roster was astronomical.
Early returns would suggest that Hagel, 23, wasn't worth the the cost. In 15 games he has only 3 points with Tampa, all 3 of them goals. However, there are a couple things you have to remember here, a) he's a young guy who's learning to play a new system and b) Tampa has him for longer than just this year, he's not a rental. While the price may have been steep and he might not be producing well through the first 15 games of his Lightning career, I think it's important to remember that learning new systems take a long time in some cases.
One of the most concerning items for the Lightning is likely Hagel's ice time. While playing in Chicago, Hagel was seeing the ice 18 minutes per night, but is only seeing about 13 minutes per night in Tampa Bay.