Which sourdough starter should i keep?
The easiest way to decide which starter works best for you and which one you like more is to bake a bread with each of them. 

I would suggest to make them at the same time (or one after the other if you don't have the oven capacity), so you can have a direct taste comparison. Don't worry about having too much bread, you can freeze part of each loaf if you don't think you can eat it all while still fresh.