I love my ViaAqua. It's got an unbreakable metal casing and an external thermometer, with remote thermostat. It has served faithfully in my 55g for at least four years without a glitch. The rest of my heaters that operate correctly are Ebo-Jager.
My 125g has two Ebo-Jagers and one Tronic, housed in PVC. The two Ebo-Jagers took awhile to synchronize, but I've got them sharing duty. Both of their thermostat lights flick on and off. But the Tronic, while having passed the bucket test, does not always show its light when heating. I trust its ability to maintain a constant temp, but since it lies to me about when it it operating, it's hard to know if it is synched up to the Ebo-Jagers or just lurking in case one of the Ebo-Jagers decides to go belly-up.