Very familiar with 9006, tried many over the years results:
9006 SilverStar - 1st replacement bulb I ever purchased. Bulb blew out was at the auto parts store already. Bought before I researched about tinted bulbs. Still have it from 2004 and still works, but looking back it's not worth it.
9006 XtremeVision - The brightest bulb I could buy in the U.S. in 2004 that wasn't tinted. 30% brighter than stock. Only one I recommend to friends and family.
9006 75 overwatt - Noticably brighter but didn't last long. Also you may not be getting 75 watts if your wiring can't handle it which means your wiring is heating up. Because of this, I don't recommend at all unless you upgrade your wires.
9005 tab modded into 9006 - worth it, but only recommend if there is a that shield in front of the bulb in the housing. Nearly all do.
9012 HIR into 9006 - Would love to try! I see this bulb at auto parts stores, still required tab cutting, but at least it's filament is exactly where it needs to be. Can't wait to try, but my XtremeVisions are still kicking.
Overall, you already did the correct easy things to get the brightest light. Remove the haze from your headlights and replace your bulbs. Next would be to upgrade the wiring or at least run a better ground which isn't that bad in many cars.
And no... though you can measure that they produce more lumens on the road in real life you cannot tell much difference when driving. Most of the time people who say they do aren't attributing it to the fact that they just replaced an old bulb that dimmed... regardless I still recommend the XtremeVisions.