Okay, this is specifically for Road To Glory. I play a 6'1" 250 Signal Caller Mike Linebacker for UF, and it's the most fun I've ever had in any career type mode in a football game. Reading an offense and recognizing what plays teams like to run out of what formations has been great. It's fun to know where a run is going because I can blow it up before it even gets started.
I finished my freshman season 6 tackles short of 200, led my team in interceptions with 10, led the FBS in sacks with 18.5, had 63 tfls, was runner-up for Heisman, and made the National Championship. Unfortunately, we didn't win because my secondary is god-awful, and Georgia beat us by 2 points. Still, Linebacker is definitely my favorite position to play for the defensive positions. You just feel like the most important player on the field and can occasionally play d-end depending on your school, which I get to do plenty of at Florida.
Cornerback is cool, but I prefer being more involved whenever there's a run. And being less of a coverage defender doesn't mean you aren't gonna get targeted. I had multiple game-winning picks and a few tds from lurking. It's just a bit better when you're the guy that's pretty much always the heart of the opposing offenses' gameplan.