Mate, I'm also in Oz, and I grew vertical HPS (1200w) for years. People have copied my system since 2004 (google it).
I started playing with strip LEDs because I didn't have enough space at my new place to go vertical the way I wanted. All I can say is, not only am I converted, but I have started to convert HPS commercial growers as well.
You talk about "changing bulbs", yet there's none of that with LED. You talk about "entire units" failing, but I've been running multiple boards for over a year now without as much as a single diode dimming on me. If I ever need to replace a strip or board, it's like $30 or so.
My LEDs have produced better yields, without the heat, with much better efficiency and none of the hassle of having to wait 20 minutes in-between arcing (turning on and off).
You would not have found a bigger proponent of vertical HPS growing than myself 12 months ago. I, too, was a LED skeptic.
But you know, sometimes you gotta try things before you form an opinion. Just sayin'
