Hi Dopey
I didn't have time to snwer your question the other night, but i've got time now.
I'll first answer what you said about the plus 50s, then talk about the polarg.
Vision plus (plus 50) globes do output noticeably more light. Cars often come with plus 30 or even plus 50 globes, so the difference might not be noticeable sometimes. If you put a new standard bulb in one headlight and a new plus 50 in the other, you'll notice it. The thing is, they won't give you extreme light difference (not like hid v halogen), because ontrary to popular belief, plus 50 does not mean 50% more light output. It means a bit longer range, and 50% more light in the useable range (varies, but it's usually 50-75m).
The plus 50s are a tiny bit whiter, because they they are brighter, but they're still yellow in the scheme of things.
As you have said, you know that a blue filter reduces light. Good.
If you want pretty, that is, whiter, you need the filter. The solution to not having less light is to put out more light, so that after it's cut, it's still decent.
This is where bulbs like narva artic blue/phillips blue vision etc fit in. For all intents and purposes, narva/osram/hella/phillips bulbs are all very good quality, and in tests, they always perform almost identically. These bulbs can be described as white. Not blueish, but just white.
These bulbs utilise an overpowered filament (still 55watt, so it won't melt your housing)to output the plus 50 light which is cut back because of the filter. Quality of these bulbs is quite high, but because of the overpowered filament, life will be shorter than standard bulbs or even plus 30 bulbs.
Now, to answer your question. I have tested both 55 watt and 100 watt polarg bulbs.
The 100 watt polarg bulb, even after it cut back light, still put out quite bright light, because it was 100 watt. I would not run these though, because i've had to repair so many cars where 100 watt globes have destroyed things.
The 55 polargs were not anything standoutish.
My main reservation about the bulbs, is that bulb life wasn't any longer than the phillips/narvas. Nor was there notieably any brighter light. therefore, I can't justify the spend.
Hope that helps.