You will have to add relays to get the benefits you're interested in. I added 4 relays -- 2 each side - 1 for each low beam and 1 for the high beams. I used 10 ga. wire for hot and grounds and used the factory wiring to "trigger" the relays. I measured 0.00V drop between the hot source (alternator output) and the bulb -- which means I'm getting 14.6V at the bulbs with the engine running. With the stock set up I was seeing about 11.5V there -- BIG difference in lumens.

Good write up here about the benefits -- http://www.danielsternlighting.com/tech/relays/relays.html