They receive mixed reviews - some people love them, but enough people have had problems that I would stay away. A good temperature controller and glass heaters is the way to go, in my opinion. I use a couple of controllers. The first controller is a Medusa, it has lasted 15 years with zero problems, but unfortunately went out of production a few years ago. The second is a Pinpoint controller, which I've used for about five years. It has also been a very good unit, but doesn't have the lighted display and over/under temperature alarm that the Medusa has.
I connect my controllers to glass heaters with the temp set at 85. That way if the controller were to stick on or the probe were to get pulled out of the water the heaters will shut off before cooking anybody. Cascade brand heaters are dirt-cheap and seem to work well.
Reviews of the Via Aqua:
http://www.petsolutions.com/C/Aquarium-Heaters/I/Via-Aqua-Titanium-Heaters.aspx#reviews
http://www.amazon.com/Commodity-Axis-ViaAqua-Titanium-Heater/product-reviews/B000HWTEFS
I connect my controllers to glass heaters with the temp set at 85. That way if the controller were to stick on or the probe were to get pulled out of the water the heaters will shut off before cooking anybody. Cascade brand heaters are dirt-cheap and seem to work well.
Reviews of the Via Aqua:
http://www.petsolutions.com/C/Aquarium-Heaters/I/Via-Aqua-Titanium-Heaters.aspx#reviews
http://www.amazon.com/Commodity-Axis-ViaAqua-Titanium-Heater/product-reviews/B000HWTEFS