When The Dark Knight Rises teaser came out in 2011, the number one complaint was the inability to understand Bane's dialogue. Between then and the release of the movie this year, Tom Hardy re-recorded every line and the difference is exceptionally noticeable.
The only downside is on occasion the new voiceovers make Bane sound too cartoony for Nolan's world. But if it means not having to replay scenes over and over to understand Bane, it's well worth the cost of momentary lapses in suspension of disbelief.