The only reason I ever found for growing outdoors in containers, was that the plant could be moved if I thought my grow was compromised. Other than that I like to give my plants a nice big hole, that I turn in all sorts of goodies. I prefer growing in a hole, but at the same time I have been happy on certain occasions when I grew in a container.
Root ball on an outdoor plant can easily fill a 5 gl container. They work, but by harvest you will see that the roots have taken every bit of room. In a hole your roots are able to spread out to find moisture.
Also Pots, or bags, dry out faster, and get hot, so they will require more work from you, which is okay if they are close by, but if you are guerilla growing bags may not be the way you want to go.
I have done both, and I guess I prefer to grow in holes. stealthier, and less work.