What are the pros and cons of going on a gap year?

I had a gap year myself so I know well how it goes, there are a lot of benefits taking gap year, however you must know what you are doing and have a tight schedule to actually make things work out for you, so here we go

Pros:
You get more time to choose what you want to study
You can aim for deferred entry (Meaning if you fail at first attempt you can re-take exams and try again)
You can save up some money for your studies
You finally have time for things you always wanted to do, yet had no time before
You now can get job experience so once you go study to other city it will be easier to find a job
It is pretty fun, I worked and yet still had time to go out and have fun
You may start learning something new (for example go for IT course or start learning language)

Cons:
If you do not have will to do THINGS then you will most likely waste that time during your gap year
When you have a lot of free time bad habits start to kick in, I mean I was not as productive during my gap year as I am now while studying in uni, so procrastination is a big thing when you have a lot of free time
It may defer your career, if you are linking your career to your education it will defer it by one year (obvious right?)

I mean in overall it comes to one question how determined you are to use that time wisely during your gap year? Because what I found out is that when you do not really have deadlines and teachers yelling at you to do things you are not as eager to do them
What I would suggest try and make so you have as little free time as possible, just use it on things that are both beneficial and pleasurable for you.