Getting 2X Boost will make leveling a piece of cake. It gives you 2X Mastery Rate on the next job. You can get it either through a random drop or through gifting. When you opt to share the 2X Boost to your friends, a popup will appear with a list of three to four mafia members. The list is predetermined.
The 2X Boost will be used on the next job attempt. Take note that it would be used even when you already mastered the job. So you must keep this in mind the next time you get one. You can only accept five boosts each day.
As always some people encountered bugs with the 2X Boost. Some say it doesn’t give them twice the Mastery points. Have you encountered a problem with the 2X Boost in Mafia Wars?