I was offered Jason Heyward for Desmond Jennings

So far, my team is looking weak at RBI, HR and even with Jennings, it is not a Runs/Stolen Base monster.

Heward looks better so far and I think has the higher power upside with a few steals, (thinking 25-15 guy) while jennings could be a 10-40 guy.

Anyone well read on either of these players?