Which one is better, AVG or Avast antivirus?

Ok I have avast because it has real-time protection and AVG used to not, as in i could get bombarded with viruses and i would only know when I scan the computer, while avast simply doesnt let them in...but i was told that now avg DOES have real-time protection...so which is the better one NOW, which has a higher detection rate, which one is lighter, what are the pros and cons of each (im installing it into windows 7 and itll be the free version of whichever i choose)