I'm very happy with my Aqueon Pros. I have two, a 100 Watt and a 150 Watt. The only complaint is that the temperature markings are a little imprecise. However, I've never gone with the markings but set my temp using a thermometer. In fact my old cheapie heater had no markings. The Aqueon Pros are the ones with the aluminum core and the plastic shell. They turn off automatically if they are out of water. They also have a red/green LED
. The red indicates heating and the green indicates the temperature has been reached. It is very easy to see if your heater is plugged in and operable because of the LED
. They have a great reputation and a great guarantee, though I've never had to use it. I have no idea about the non-pro models. They are the same brand, but definitely not the same heater.