I have 6000k high and low and I use my high beam on back roads all the time. In daylight it helps to keep you visible, and at night... well, that's obvious. Cost effectively buying high and low beam is worth it. Just because a high/low kit is - say - $200 usually means purchasing the low beam by itself is more than 1/2 that price.(DREW @ Jan. 17 2007,00:12) You dont need both ! The low beam is all I ever use... Trust me on this.. Ask others who have them. Also the 5000 k is the whitest. you can wear sunglasses at night and see Way Better than with stock bulb.. but if you want both,consider the projector high beam is focused for the stock bulb.
Projector beams are usually 55 watt halogen. I'll agree that it is better than having stock by itself, but the cost of projector for just the high beam is much higher than purchasing a HID high/low kit.