In HS, Tebow was about 6'3 220 of solid muscle. He benched 185 38 times as a junior. He was (and is) a power runner, not a speed guy, turning in a 4.69 at a Nike camp.
Gilbert is listed at between 6'4 200 and 6'4 210, and he's more of the skinny type who will fill out. He's not the kind of guy who's gonna run you over, but if he sees room to run, he might be quicker than Tebow to hit the hole.
But I'm guessing Gilbert isn't gonna be rushing for 20 TD's a season in his college days. They are COMPLETELY different quarterbacks.