I have thrown all three here is my take. The saint is a lot like the flow but a little shorter, but not by much. I think it can compliment the river and it will not be as long as a flow so it will fit in your bag for sure, if not the mp will snag it up quick. The river has the same nasty glide, but where the river turns a lot and will hold the anny line the saint will want to fade back at the end of a anny line. The gold line saint is a hyzer flip maniac!!! it flips up to flat and tracks right just a little then straight with a gentle fade. I remember the flow to have a more pronounced turn and fade, more r to l movement. hope this helps YMMV