The new Tru-Feed Magazine uses a straight feed, low tension spring system that allows the player to use a wider variety of paint and is less affected by hot or humid conditions.
For TPX users who currently have the 8-ball magazine, changing to the 7-ball magazine may not be necessary for a few reasons. First, the 8-ball continues to work well for many players and second, there have been other updates to the original TPX which could also affect performance.