I own the H600w and the Armytek Wizard. I used to own a Wizard Pro, but I lost it. I frequently cave with 3 individuals who also own both. A Wizard's performance is roughly equivalent to the H600 series, and perhaps a little closer to the MkII than the MkI. The Armytek is heavier (I can't tell a difference when it's on my helmet), because the body is bulkier... but that's also a good thing; the Armytek is clearly designed to take more of a beating, which I personally appreciate. The "spread" or beam profile of the Armyteks are not as concentrated as the standard H600, and most similar to the H600f. That means you can't see as far ahead with the Armytek (keep in mind that, even so, it still throws farther than the average headlamp you will find in a store), but that also means that you have more peripheral vision, which is also my personal preference. The tint on the Wizard is awesome; believe it or not, it makes my warm H600w look purplish and cold). As for trustworthiness, I have owned an H600 that failed in a cave, and my cousin has owned a Wizard that has failed outside a cave, so I consider it a draw. Look these up on candlepowerforums... it happens from time to time with both these manufacturers, and I'm sure it's not just these two. That's where warranty period comes into play, where the Wizard has an unbelievable 10 year warranty (vs the H600's 1 year). Sorry for this turning into a sales pitch, but the Wizard (non-pro) is also $15 cheaper. Is it a viable alternative? Yes, I definitely think so.
Happiness can be measured in mud/in².