Gilbert should be an excellent fit next to Harris, assuming Harris gets back to full strength (huge if!). But if he's not next to a very good 1-technique, he's wasted. Best comparison I can come up with is a lighter, quicker Cory Redding the year the Lions had great success with Redding and Rogers. Last year no Rogers = ineffective Redding. Gilbert is that same sort of tackle that can thrive next to a good nose but will struggle if required to do too much.
My scouting report:
Summary: Incredible athletic prowess for a man his size. Very quick burst off the line. Has the strength and length in his arms to stay off blocks, knows how to use his hands properly. Good play recognition, isn’t fooled by play action or draws. Great lateral quickness and agility for the position. Closes on the ball with authority and has some pop to his hits. His dad played in the NFL, which speaks to his football upbringing. Can be effectively neutralized when the blocker gets to his pads, does not have the strength of most tackles to unlock. Loses his leg drive and gets upright when engaged. Not a strong run anchor. Some observers question his fight; has not always held up against nasty mauler-types. Could be a tweener; best fit is probably at 3-4 RDE but he’s not physical enough for most teams who employ that scheme, and he’s too light (and he plays light) for a 3-technique 4-3 scheme.
Forecast: Regardless of whether you believe the YouTube of him jumping out of the pool, the fact that it’s credible speaks to just how physically gifted Gilbert is, and he dominated in postseason bowl workouts. A draft board riser who will come off the board in the 25-45 range, though there is considerable risk
The one knock that consistently came up against him is that he doesn't handle getting popped well, doesn't like the real physical attacking O-linemen. It shows up on tape if you catch their games against Boise State and Idaho--they fired out and got physical with him and he was not the same player. Idaho consistently ran right at him and had loads of success, though Gilbert did make a late pass deflection and a great chasedown tackle on a draw that allowed them to salvage a win. He absolutely destroyed some pretty good guards during East-West practice drills, esp. the pass rush drills.