Repeating what I said in the Texans preseason postgame, on the play that Zappe hesitated on the long ball to Thornton, imho Boutte had 3rd pick overall Stingley Jr. beat on the other side (off of press) if Zappe decided to roll the dice that way, and that's before Stingley fell down. It was only one play, but it was a glimpse.
Repeating what I said in the initial post draft thread, his 48.27 400m in HS (initially thought to be 47.82 but that's Mekhi Boutte's time) tells me he potentially still has incredible speed endurance. That means he gets to retain his overall speed even after only 45-60s of rest in between each play. At crunch time, when you see guys huffing and puffing, Boutte won't need to go to the well.
Side note: fastest 400m runner in the draft this year, Derius Davis, already has a punt return TD this preseason.