I would say yes in a heart beat. Williams just off his bye and he should be ready to explode. As for Grant he usually has a strong second half of the season. Colston is valuable but New Orleans spreads the ball to everyone, Manningham buzz is dying off, Smith is the clear #1 and I think the Gmen go to Jacobs/Bradshaw and rely on the run more. Felix Jones is a great flex.
I think the deal favors you greatly, and opens up a roster spot for you to pick up a decent WR off of waivers.