Sorry to revive a dead post but this popped up when I was trying to see pothos vs potato information and I figured I should update this.
the monstera definitely won, by a mile, the pothos is growing very strong and is as thick in the stem as my finger, but the monstera is fruiting, has 32 inch leaves (no sunlight) and has roots that span 6 feet by 3 feet, definitely the winner for large tanks but I would not recommend it for anything shy of 200+ gallons just because the roots will take over you tank, I can add way more photos if there is interest, there is very heavy plant load in this tank with the monstera but even when jam packed with goldfish the plants keep nitrates to basically 0, it got so strong I had to add close to 30 pounds of crushed coral just to keep the KH from crashing and it’s really done amazing keeping the water “clean”.