Catching up with the big boys.

The 2006 roster included five (5) players 6'5" or 6'6"

Projecting the 2015 roster I see eighteen (18) players 6'5" and taller.

Bigger, stronger and faster is what it is all about.

Not.

If these guys are also quick, of course it mattes. If they are slow, not so much.

The positions you see the really tall guys are on the offensive line and at TE. All the top schools want to recruit those big linemen, and Ohio in the past has had to make do without as much size there. Bcat2 is right that Ohio is closing the gap a little, with more taller TEs, and a big jump in height on the offensive line.

TE is a little taller. Here's the picture in 2005-6 at TE:
6-5 David Carter, Kody Carr, Adam Olsheski, Nate Caldwell
6-4 Rudy Sylvan, Dave Cody
6-3 Corey Logan, Thomas Christy, Andrew Mooney
Average 6'4.1"

And TE today:
6-6 Mason Morgan, Connor Brown, Ryan Carter
6-5 Troy Mangen, Brennen Boland
6-4 Zach Hawk
6-3 Davon Henry
Average 6'5", or a difference .9" taller

The change at OL is a bit more. The offensive linemen in 2005-6:
6-4 Coppage, Bush, Wesley, Shelby, Rodgers
6-3 Schussler, Leuck, Eynon, Knabb, Miller
6-2 Nelson, Johnson
6-1 White, Stuck
Average Height 6'2.9", Average Weight 290lbs

For 2015:
6-6 McQueen, Watson, Lowery, Murdock, Anderson (new JUCO)
6-5 McCray, Gibbons, Dudziak, Pauley
6-4 Lucas, Adams, Alcorn
6-3 Powell
6-2 Pruehs, Wood, Langenkamp
6-1 Cooper (new JUCO)
Average Height 6'4.3", Average Weight 294, so a gain of 1.4 inches.

Doe it matter? Well, in theory a bigger offensive line is a good thing, but I think we'd all agree that the 2006 offensive line, and the 2006 tight ends were much better than the 2014 versions. The key is that, while size is important, age and physical maturity are far more important. In 2006 the top players at those positions included nine of ten upperclassmen, nearly half were Seniors, and all had at least 3 years experience at the college level:
Coppage, Sylvan, Knabb, Logan, Christy - R-Sr (5th year)
Johnson, Shelby, Miller - R-Jr (4th year)
Bush - Jr (3rd year)
Eynon - R-So (3rd year)
Average Experience at start of year = 3.3 years

By contrast, last year the people at those positions included only three of ten upperclassmen, no Seniors at all, and not even half the experience:
McQueen, Lucas, Powell - R-Jr (4th year)
Watson, Henry - R-So (3rd year)
Mangen - So (2d year)
Morgan - R-Fr (2d year)
Lowery, Pruehs, McCray - Fr (1st year)
Average Experience at start of year = 1.5 years

You are always going to struggle offensively if you have that young of a group of players up front. That's just a fact of life. I have a friend that bets on football games every year, but only the first 2-3 weeks of the year. His sole criterion for which teams he bets on is the age and maturity of the offensive line, and he does pretty well. (He doesn't bet after the first few weeks of the season because by then the performance of the line is factored into the overall performance of the team. Most people look at the skill players like QB/RB, and significantly underestimate the importance of the offensive line).

With another year in the weight room, and another year of experience, the line next year will be a little closer, experience wise to 2006. I think these are very good players, and likely better than the 2006 players. With another year in the weight room, and another year of experience, they will do much better in 2015 than they did in 2014. And their size? Yes, I think that will help, too.