You can't go worng with either Penquin or Aqueon filters as both are great value filters. Don't let the flow rate difference be your deciding factor in choosing the filter, because the filter media volume is just as important. A higher flow HOB without more filter media will only get clogged up faster. All HOBs have small filter volume anyway so they are only good for mechanical filtration and not much else. Don't let the manufacturers claim to fool you that their products have more bio filtration because they all have negligible bio capacity.
Aqueon has a unique design in that the motor is located inside the tank, so it will self prime and run quieter than Penquin and all comparable fiteres. But I don't like its filter media design because there is a slot at the bottom to lock into the box so it's difficult to make DIY media that seals tight. Penquins are excellent and reliable mechanical filters, even though I don't care for or use its signature biowheels.
