I've been testing with a PAR meter for a few years now. I am an engineer by trade, so I tend to be kind of careful with measurements. Lenses on the LEDs mean a lot depending on your tank depth and the surface area covered. It can double the PAR in a deep tank.
The two fixtures rated at 120 watts measure the same PAR regardless of LED
number in my measurements. The longevity of the emitter is controlled by the wattage it is driven at and the parts operating temperature. Drivers need to do just one thing..provide smooth DC
power. They cannot effect the color temperature of the emitter.
I am aiming to grow corals and as a diver I don't like the fluorescent gaudy colors some artificial lighting causes. The reef doesn't look like this even under photo flash. Everyone to their own though.