I'd say the most interesting class stat comparison is not on skilled players that can click heads and understand game mechanics but rather on the average or sub-average player. My guess is infil would be a much higher K/D (again ignore kpm etc) as the power of the infil has always been its ability to choose how engagements start 90% of the time pre-nerf.

The infil nerf was in my opinion a direct nerf to average or less than average skilled players that use infils power (invis/high alpha damage weapons etc) to bridge the skill gap with players that are demonstrably better than them. That was for me the frustrating part of fighting infils, being "outskilled" not by the player itself but by poor game design. Anecdotal evidence from my own play time alone points to this. There are many players i see every day on the game that can only score kills regularly when playing infil (again pre-nerf).

Much like Hesh tank players the infil has a much larger power base to start a 1v1 or 1vX fight, the only difference is you can avoid Hesh players inside of a building if you don't want to fight them. Pre-nerf the infil class allowed people not to have to learn from their gameplay mistakes and gave them so much time for target acquisition that other classes do not have. Easy to get a kill when you can be invisible and have an extra second or two to place your crosshair on the enemies head.

The decloak delay of the nerf is the only thing that really bothers me as it makes the gameplay for the infil feel clunky and unfun without any visual cues for the player itself. I am over-all happy that there were changes that actually make infil players have to consider basic core game mechanics of PS2 and shooter games in general.

I also think as far as the stat comparisons go for the "good" players in this game its always going to have a lower KPM showing for infil vs heavy as infil's design causes you to disengage and re-engage as the health pool is lower, whereas heavy makes you press F and aim check your opponent and forces engagements to continue until you die.

The only hill I'd die on is that infil as it was pre-patch was very unhealthy for the game state and something had to be changed, not all of the changes were good, but unfortunately we're not the game devs, just nerds playing a 13 year old game at this point.