Re: Just installed relays on my dual rounds and WOW!!! (alphaDUB)
YES YES OH GAWD YES. Night and day difference, both in brightness and beam spread.
I currently have the euro aero lights - H4 bulbs (55 low /100 hi) with city lights. They're certainly noticably better (both low and high beam) than the stock USA model lights, but also different in some key areas:
1) The low beam cutoff is more distinct - almost unnerving, in that there's a pretty sharp horizontal cutoff, above which there's very little light. On curvy mountain roads you can get into a situation where you're coming into a downhill left hander and not see the entire road because you don't have quite enough beam scatter. With fogs it's OK - they make up for it.
2) The low beam pattern ("spread") in front of the car is more even - not splotchy like the stock USA model aero lights, and definitely better than the USA spec 7" rounds (GTI style).
3) The bulbs are slightly brighter in "stock" 55/60W configuration, with relays you can run 55low, 100W high (which is what I run) and get some "aircraft landing light" high beams - like laser beams. I want to try some 80 low / 100 hi but have not yet, I'm guessing that may tip off Johnny Law - and in NJ there are car inspections and they DO check for DOT lights (so I had to keep the stockers)
4) The high beams are night and day different - better, more focused, VERY bright.
The aeros look almost ENTIRELY stock unless you know what you're looking for - which is an advantage, stealth-wise. The city lights do kind of give them away, though. I've had my wife following me in my car and the lights have a little of that euro-look to them, they're not just bright white blotches like USA spec lights - you can see some pattern in the lights themselves, but nothing obnoxious (again, you have to be looking for it to see it).
I had the quad round euros (7" outside, 4" inside) on my old '91 16V GTI - the euro quads are better than the aero euros on high beam (twice the lighting - where the aeros are only "amazing", the quads are "unbelievable") but both euros are comparable (very good) on low. The USA dual-rounds are awful, blotchy. I wouldn't run >100W in any light, though - there's diminishing returns with higher wattage, and a lot of heat and amperage to consider.
USE RELAYS! you don't want to fry wiring. It smells awful, and roadside fires are ugly things that spoil other Dubber's commutes.