What would be perfect is if you could arrange to meet a fellow Bronco friend with Halogen H4's on a dark road somewhere and get a head to head comparison. I'm OK with my H4's, but I am always willing to upgrade a bit.
Sealing may be an issue for me. I don't have inner fenders on my Bronco. I have not had any issues with my Hella H4's, they came with a rubber boot to help seal up the area around the socket though. I don't normally go mudding, but I do occasionally do deep water crossings. Only once did I submerge the headlights though. Even my H4's would have had issues with that though. Luckily that was when I was running sealed beams.
Dan