any opinions on the galaxy grow amp?

Im looking to upgrade my 600 watt phantom ballasts. i love phantoms ive been running them for 5 years now without a problem. i want to upgrade 1000's. does anybody have any opinions on the galaxy grow amps? should i stick with phantoms?http://www.amazon.com/Galaxy-Grow-Amp-400-600-1000-Select-A-Watt/dp/B00AYES9KK/ref=sr_1_1?ie=UTF8&qid=1419967544&sr=8-1&keywords=galaxy+grow+amp

I've never used them, and I'm sure they work fine, but from now on I stay away from ballasts that are actively cooled (fan). Fans go bad and dirt builds up in ballast.

- Jiji