I have no love for highway pits but to play if off like an HSR pit is some quaint little light rail is simply farcical.

You're being dishonest or ignorant. The fact that you compare max-width of one to min-width of the other rules out one option. A pit is a pit. You're limited to crossing at a few specific points no matter how narrow it is and traveling to those points accounts for the bulk of the distance covered. The physical width only matters if you're evaluating the neighborhood for visual appeal and not actual livability. "Quiet most of the time" doesn't really count for much because people acclimate to the background noise levels and that one train per hour is just as jarring as that one motorcycle with the insane exhaust per hour. At least with subways and airports it's every couple minutes so you get more used to it.