Cooler is pretty powerful. He took on Goku and Vegeta teaming up, but in the end it won’t be enough. In Cell’s Super Perfect form he’s a Solar System Buster! It’s nearly impossible to take him down. Cooler’s good, but even he’s not that good. Cell’s just stronger and faster. Cell wins.
Update 9 19 2020 Cooler managed to even take out evil Heroes Goku and beat a bunch of ghost warriors. I’d say he has the edge here. Cooler wins.