Not sure if I'd take this trade. But I will say this:
1. I love this team, but I shouldn't. It isn't a championship team and it may undergo many more changes before it starts to look like one. Hard to say, but we can't fall in love with these players. They're a game over .500.
2. In the NBA, talent always beats effort (unless you have a sliiiiightly more talented player who doesn't play as hard as a sliiiiiiightly lesser one). K-Love is the better talent, hate to say it.
3. Brad Stevens. The man turned Jordan Crawford into a starting PG. We have no idea what a superstar talent will look like under his guidance, but we do know he can take mediocre - solid players and make them look much better. If we did trade Jae, he would look worse on the team he's traded to - I'd be willing to bet.
Finally, as many have pointed out, we can't add another 4. We'd have to accompany this type of trade with a parallel deal to clear space. Still, when we talk about building around players, we mean grade-A talent - not hardworking filler, as great as they are to have and as much as they overachieve.