I initially bought (3) different sizes and compared them to the old metal halides I Had in the other bays. I settled on the 85w because they were much brighter than what I had plus gave me the most savings. I also have the White Extrutech wall panels that help reflect light.Just curious, how did you decide that the 85 watt was going to put out enough light to equal the 175 metal halide? On their website they also have 105 watt and 150 watt. All of them seem to be less lumens that a 175 watt metal halide produces and yet I can see in your pictures that the clear choice would be the flourescent. A couple of years ago I installed some new wall paks that had a 150 watt metal halide pulse start bulb in it. These produce 9800 lumens, way more than a 175 watt probe start metal halide. I still have some old probe style metal halides that need replacing.
If undecided, I would suggest you do the same. Order (3) different wattage bulbs and do a comparison...That way you can compare to your other bays before deciding on what works best for your situation.