while it does most certainly delete heavies... ripping off 90% of the hp is a bit inaccurate... as i tested on cheatmods it usually kills around 60-70% of the HP of a tiger even from the rear... it usually needs an SU-85 or some other AT unit to finish the kill...
Isn't that normal than? You spend munitions + tank and you need another tank to finish the job. I mean, it's a cheese strategy but I've seen KTs and Tigers get out with smoke, either because there were no supporting units with AT capability or the affected player smoked around the heavy tank. It's even more so since you really do need a high penetrating tank to finish off a KT. It's 375 armour will certainly mean that not every shot will penetrate at max range from SU85. Just my two cents.