I've owned and tracked both.
For me, the '40 is much easier to drive. The power is applied to the pavement in a way that hooks up and moves the car forward. Very little wheel spin. It's also much more comfortable. One can tell that it is an endurance car, meant to be occupied for hours at a time.
The Cobra was a handful. Fast, but I really had to work at it. I used to think she was trying to kill me if I didn't give her my full attention. It was downright dangerous with the BF Goodrich tires it was delivered with. Sticky race rubber tamed her a bit, but when I hit the gas, she was as likely to fishtail or go sideways as to go forward. Entertaining, for sure. But a completely different driving experience.