I have been an E-Code H4 headlamp fan for about four years (and have converted my daughter's car & mom's truck) We have Hella lenses, but for my birthday a few weeks ago, I bought a set of IPF H4 lenses, an 'upgrade' harness, and a pair of halogen 145/90w IPF bulbs. I can't wait to get them installed in my DD.
The upgrade harness is probably more effective in older Jeeps, where corrosion and degradation of the OEM wiring has occured. I made my own for the MJ, but this time I wussed out and went for the IPF "plug & play" dealie.
My past experience has found the IPF J bulbs to be about equal to Hella 100/80w halogen in 'perceived' performance...but at three+ times the cost of the Hellas ($ 75/pr vs 22/pr, shipped). The J's lasted about 1 year, but I normally get somewhat less than that out of the Hella bulbs. The advantage (supposedly) from 'exotic gas mix' bulbs like the IPF J and Hella Xenon is one gets light output equivalent to a higher wattage bulb...without the extra current draw that the more powerful bulbs demand.
I :dunno: about those Auto Zone lenses...it appears that the reflector inside has facets as opposed to the cut crystal lens' of the Hella or IPF. If they work well for ya and don't blind oncoming traffic, then I guess you are on to something.
Rensselaer Polytechnic Institute's Lighting Research Center has done a bunch of tests on OEM style lighting, and there are a pile of SAE papers written to show for it. Very good reading with lots of insight
www.lrc.rpi.edu/programs/transportation/index.asp
While these experiments didn't offer a direct comparison between 'Brand A' and 'Brand B' they offer up some comparison between HID and halogen...using existing european spec (E-Code) lens designs. I would like to see an objective test of the different brands of bulbs...to see what is smoke & mirrors, but until then, I'll stick with respected brand-name products.
FWIW most of my night driving is done on unlit rural roads, where distance as well as periphial illumination is important (lots of deer). NC is using a lot of reflective thermoplastic roadway striping (better than paint with glass beads) as well as reflectors along the centerline...so 'seeing the road' isn't as much an issue as seeing the beasts. On our (few) roads lacking reflectors, the focused light output and e-code's wide low beam pattern is appreciated. I don't drive my Jeep at uber-legal speeds, so getting further advance warning of road hazards helps my reaction time.