Sometimes I make the statement that I prefer a 3 1/2 - 4 lb., crisp, clean trigger on a shotgun. But, the reality of it is that I shoot some shotguns well that have a bit harder trigger pull than that and they seem perfectly alright. I have come to the conclusion that all triggers of the same "weight pull" don't feel the same. They may both be clean and crisp, with no drag or creep, but a slightly heavier trigger may feel lighter than it actually measures with an accurate trigger pull gauge.
I believe the shape of the grip, and the position it places your hand in relation to the trigger, causes the leverage to change as your finger engages and pulls the trigger. FWIW, it seems to me that I can tolerate a slightly heavier pull on a straight gripped gun than a POW, semi-pistol, or pistol grip. Again, I think it's the positioning of the hand, finger and trigger that causes that.
Just some of my meandering thoughts on a rainy mornin' in Jawja.
SRH