It is very safety to park your there, they have some people there for 24/7.
No matter how early or late being airport, they have shuttle bus to drive you to "Park N Fly", again 24/7.
One more tip: before parking your car there, go to their website to download coupon, which will save you lots of money. 10 days probably will save you at least $20 with coupon. You only need to show it to them when you pay parking fee. Remember where keeping your parking card which you will receive when you get in, it shows your parking lot area number, so the shuttle bus driver can bring you in front of your car.
10 days probably will cost $50 - $80 with your coupon and based on their monthly promotion.
Good luck and have fun with your trip.