Like with all the other birth control methods there are some pros and cons about this one. As i am thinking about it myself, here is my summery:
pros:
-you don't need to take medicine daily (or forget about it)
-long lasting effect without sterilization
-you can use while breastfeeding
-once you stop its easy to get pregnant
cons:
-side effects, such as irregular bleeding within first 6-12 months (sounds a bit scary, doesn't it?)
The most important thing we have to remember when we choose a birth control method is that almost none of them give a 100% guarantee.