It depends on your outings. The Banana Bag is for short outings: light, compact, fast. The CaravanBAG is for long days and everything else — integrated hip seat (meaning you can use it as a supplementary carrier for babies over 4 months old), multiple attachment points, large capacity.
If you're still hesitating, look at how long you go out on average. Less than 4 hours? Banana Bag.
More? CaravanBAG. And if you don't want to choose, the two complement each other perfectly.