I went to my local Advance Auto store (was Western Auto) and saw that they sell a Sylvania headlight bulb they call Extra Vision or something like that, and lists as 9004XV I believe. Said to be 20% brighter. (They also sell a "Cool Blue" bulb which is supposed to mimic the look of a high-intensity bulb.) They cost about $11.00 each.
Has anyone tried these? Are they in fact brighter? I'd like to get a bit better output but am not interested in going the Euro route. I've read negative things about the PIAA bulbs, which look "whiter" or "bluer" but actually put out less light.