It's the old argument of brightness again. Believe it or not, during daytime I run a 21 Watt Ba9s yellowish halogen bulb in the parking light socket European units happen to provide. That's enough to be seen and you will stand out as a motorcyclist. You want to be noticed, you don't want to annoy oncomers. There are documented cases where irritated oncomers have steered their vehicle too close, to teach that biker a lesson. Recent research have proved again - as a matter of fact, it's just out - that blinding by too bright lights is the #1 annoyance in European traffic and it is so by far. In most countries the headlamps of locomotives are not spectacular bright and most I've seen were yellowish. For a reason.
What good is brightness, when you yourself become blinded by road signs that, overfed by your output will throw extra light back in your face, resulting in a longer period for your eyes to adapt again?
This brightness thing is just a childish fantasy that some folks' mind will drool on, especially when they are looking for something to do with their bike, no matter what. Realise that for many, buying new stuff, is no more than an antidepressant and it is known to be addictive.
My tip: optomise, but respect the law.