Being in the SEC didn't seem to affect Missouri (traditional bottom feeder in the Big 12), Ole Piss and Miss State and even Vandy for a few seasons. Continue the debate.
Mizzou wasn't a traditional bottom feeder in the Big 12 under CGP. They had several 9 plus win seasons, and even a BCS Bowl if I remember correctly. And while what they've done has been impressive, they've beaten one SEC team with a winning conference record(UGA) in the two years they've won the East.
Mississippi State recruits in the 25-45 range, which is about where UK will recruit. They've had ONE year with a winning SEC record in Mullen's tenure(going on 7 years), though they've had a couple of .500 years.
Ole Miss recruits in the top 20 usually, and they have had two seasons with a winning SEC record since the 09-10 season, with a couple of one and two conference win years. They should give UK fans some pause that are hoping for success based solely on recruiting rankings.
Vandy was similar to Mizzou with a very favorable SEC schedule, only their OOC was even worse.
My point with all of this is that it's tough to climb up in the SEC. And, aside from Mizzou(only been in SEC three years), the others have had more terrible to mediocre seasons than they have good. They have competed in conference on a couple of occasions, but aren't consistent contenders, and haven't had the success many credit them with because of their most recent seasons.