As Joe(Trelja) mentioned, upgrading passive parts in a crossover doesn't necessarily guarantee better sound. Perhaps the "major leap forward in resolution" and "accuracy" was pointing out weaknesses elsewhere. Then again, replacing inductors with equal value but different AWG/DCR may change the crossover point making the speaker sound brighter and more aggressive.
With Bud's(or anyone else's) first order series crossovers, there are a minimum of passive parts and everything matters. Say you go from a junky 18 or 20AWG coil to a 12AWG Goertz to provide maximum protection for a tweeter, you will hear big differences.
Joe and I have a friend who designs first order series crossovers for the "C" cabinets. After selecting the drivers he wants to use and the optimal crossover point based on computer modeling, he then goes with good quality coils, caps and resistors(if used). Then he spends many hours/days voicing the speaker by making small incremental changes to the values of the passive parts. As Joe said, sometimes it's "trial and error" but, like fine tuning a cartridge, when you get it dialed in, it's worth the effort.
My "C" satellites use the newer OW-4 Hiquphon tweeter which is a huge step up from the old OW-2 with ferrofluid that Bud used to use. The midrange driver is a pricey but excellent ScanSpeak and the entire external series crossover consists of one Mundorf Silver/Oil cap(soon to be replaced with Dueland Cast) and two Goertz 12AWG inductors; no resistors anywhere! Add in the matching subs, good down to 20 Hz, and as my designer friend Joel will tell you, we'll put this system up against anything on the planet.
