So Sunderland have won just 2 out of their last 22 league games. To be honest I do think that Martin O'Neill is a very overrated manager. Like Redknapp he is very popular with the media, and is also good friends with Ferguson, which helps enhance his reputation.
Seemingly his only transfer policy is to waste money on overpriced British players, while other mangers are able to sign better quality foreign players at bargain prices.
I always thought that Strachan, who was unpopular with the fans due to his Aberdeen connections, did a better job than him at Celtic. He spent less money that O'Neill, but won 3 consecutive SPL titles and twice took Celtic to the knockout stages of the champions league (which O'Neill was unable to do). O'Neill lost out in the SPL title race to McLeish (who was not exactly an amazing manager) and a pretty weak Rangers team twice in 3 years.
He spent a lot of money at Villa as well on overpriced British players and ultimately that's why Lerner got fed up and balanced the books. That being said I can understand why Wycombe and Leicester fans love him as he did work wonders at those clubs. The 2000 League Cup final still grates