Just spent an hour or so looking at tape from the top 6 OGs in the 2014 class; Xavier Su'a-Filo, Gabe Jackson David Yankey, La'el Collins, Cyril Richardson and Tre Jackson. All of whom are expected to go in the first 3 rounds next year.
After that I now have them ranked accordingly:
1. Gabe Jackson, Mississippi State
2. David Yankey, Stanford
3. Xavier Su'a-Filo, UCLA
4. Cyril Richardson, Baylor
5. Tre Jackson, Florida State
6. La'el Collins, LSU

N.B. Yankey and Jackson were noticeably a class apart, almost nothing between the bottom three.