JoeS4

too much light output for more blue tint IMO.

SoSlow

5000k has about 100 lumens difference compared to 4300k - 20% reduction you claim is too high

AVANT S4 KING

high of a claim.

Technically, 4300 produces more light, but not 20% more.

HIS4

600 lumen decrease from 3200 is about 19%.

I couldn't find any specs on the Philips lamps but I would assume its pretty close.

SCSI

Brand name bulb will burn much brighter at the same kelvin temperature with Philips 85122 being the brightest. When I compared the 5000K bulb that came with the kit (Apexcone) to the 85122 using my camera light meter, the Philips bulb was roughly 60% brighter on the same 35W ballast.

There is simply no 50W HID bulb out there besides DL50, which is like 3500K and almost a $100 a piece (good luck finding one).

Overdriving the bulb will bring the actual kelvin temperature down slightly, so my 85122's are slightly yellowish and I'm looking to switch to the 85122+ as soon as these are done. The "+" bulbs are supposed to burn close to 5000K.

retrosolutions

They are 35w bulbs, please do not make generalizations based off another brand. These use real higher wattage bulbs, hence why there is still a lifetime warranty on them. In fact, the 55w bulbs from our manufacturer will not even operate on 35w ballasts, so it shoots that theory right out of the water.
For us to back up a "low quality" bulb as you suggest with a lifetime warranty does not make much business sense, so once again, please do not generalize.