I thought about hearns too but there were plenty of fights were he took a lot of punishment. Take the first leanord fight for example. Leanord was a very big puncher at 147 and Tommy took a lot of big shots before finally going out. His chin may not be top notch but I wouldn't call it weak either.
Haye actually enhanced his chin reputation tonight for me. He took some hard right hands without flinching, his problem is his defence. His chin is OK, not much better, but at heavy, he needs to keep his hands up.
Worst chin ever, I agree, but certainly not a good fighter. He would qualify as worse fighter ever, with an even worser chin.