The problem is most people do not know how to properly aim their headlights! First the hid bulbs may be centered a little different than the H4s throwing the aim off, or the aim may be off a little to begin with. With the halogens it may not be as noticeable, so when you add 300% more light it makes a big difference. As most people know as you get older, you need all the light you need, so I have HIDs on all my cars and trucks, and they are properly aimed to put the light on the road, not up in someones eyes, and they are 6000K Daylight color, not that stupid blue or purple that is trendy, but puts out less useable light. Being an ex proffesinal driver for most of my llife, I believe in safety and having as much visability as possible at highway speeds at night.
Another thing, it's a misconception that HID draw more power, they draw less than the typical halogen, another reason I use them. All my Datsuns have all leds and hids to reduce load on the alternator, my heater no longer slows down when I turn on the head lights with the wipers on.
I tried the relay and heavier wire thing on a 280Z I had a few years ago, and it made no difference, next tried a 80 amp GM alternator, still had dim lights!
Do your research before bad mouthing a product, also they are not that expensive, I just paid $60 for a conversion for my 1200.