I would think UF is the biggest roadblock of UK being 5-0. Reading the UF website they are expecting a big season, claiming 9-3 is their floor and a win over UK is a lock. I think they are closer to 3-9. They open with a preseason Top 10 team, Utah, who will likely be missing its QB and very good TE. A video of UF's practice is floating around with their new DC, the DL are all 75lb overweight with big bellies hanging over their belts, they going to wilt in the altitude of UTAH. But if the can pull off a win, they are going to be quite a bit better than I thought.
Now about coming in to Athens 5-0, of course UK can win, UK is good and very physical. But this is Kirby's best offensive team. Beck is bigger, better arm, quicker release, but his question marks are can he get into the right play pre snap and be as effective on 3rd down. It will be an upper class offense at every position, 5 receivers with 500+ yards and 3 backs who scored in NC game. Defense will be like the last few, deep, very fast, good tacklers will play lots of kids, near 30 on defensive rotarion.