I don’t see why would anyone play it over the Challenger
Smaller profile/turret profile?
But yes, when AP is in a better state the Challenger is one of my most favourite tanks (speed, rate of fire, turret traverse, reasonable turret armour versus less potent enemies it can face). Also a better stock grind since I am sure the 17lber beats the 77mm.
Comet is a better hill peeker (well not really peeking when you have no reverse).
Plus at the end of the day it is back to being a same BR alternative if you need to bring more vehicles to win, rather than lonesome at 5.7.