They can be described as having a more "defined" sound. Move a 4-pole cutoff around and the signal says loud and clear "I'm not that anymore, I'm this!"
It needs to be emphasized that the aural beauty of 4-pole filters is most evident with lowpass filters. Bandpass and highpass may not benefit quite as much from the increased steepness of boundary.
Why? Well, you need to have some "meat" in the resulting sound, and most of the guitar signal lives in the basement. A bandpass filter with 4-pole steepness on each side of the passband won't leave you with very much content as it sweeps up, and may provide kind of an aural "shock" as it sweeps down. A shallower slope leaves some substance and a bit of audible fundamental in there. In some ways, what one wants is a bandpass filter that is steeper on the treble side than on the bass side, and behaves more like a cascaded 2-pole highpass into a 4-pole lowpass, with their corner frequencies just staggered enough that the passband has acceptable width.
As you can imagine, a 4-pole highpass filter on its own can have limited use in the guitar context. I can think of plenty of uses for a fixed 4-pole highpass, but a swept one only has limited application.