Well bubble-top on later models of Jug was a bad idea, many pilots from attack squadrons don't like them and stay with "razorback" models. The legend of P-47 is about his ruggedness and ability to withstand some absurd level of enemy fire. That heavy armored cockpit save more pilots lifes then some plastic bubble canopy. Maybe it's only me but I like when behind my back and head is a solid steel armour plate.