How safe is Quito, Ecuador?

I wanna go study spanish there but I hear people saying Mariscal is the place where everything is and is fun and all the clubs, restaurants, etc are there.

Then I read some tourist guides and see other people saying Mariscal is the most dangerous part of Quito and you should avoid it.

So what should I do?

I just spent several months in Ecuador, with the majority of my time spent in Quito. While I found it was relatively safe, you do have to be aware of your surroundings and definitely watch out for pickpockets (in the Mariscal you need to watch the street children, they'll try to sell you candy with one hand and dig in your pockets with the other). I didn't hear of much crime other than pickpockets and a few stick ups (try not to carry an excessive amount of cash and same as you would in any US city, walk confidently with your head up and be aware of your surroundings - stay in well lit areas) My friend that has lived there for 2 years feels that it is not safe to walk around at night alone (especially for females), except for in the Mariscal where lots of people are out. I walked alone in the Mariscal and felt completely safe. Generally I would just recommend that you be aware of your surroundings, take extra care at night, and watch for pickpockets.

Like any big city, Quito has its bad areas and good areas. It is all up to how street smart you are, not exposing yourself.
Mariscal is a pretty popular place to hang out, bars, restaurants and clubs, however, you do have to be careful late at night, unfortunately it is foreigners who they target the most (carry a lot of money).
During the day you should be fine, as long as you are aware of your surroundings. At night, if you are out clubbing or at a bar, I recommend you call a taxi ahead of time, instead of hailing one in the street. Try to have a reliable taxi co. phone number with you (you can get this from the yellow pages)

The modern part of the city of Quito is safer (north) than the older and poorer (south), el "centro historico" or the colonial area of the city is beautiful, but pickpockets are everywhere, so just be careful with what you bring with you.

Just play it smart, and you'll be fine.
Good Luck and enjoy our beautiful country!!