I'm not sure the Spider sense CAN counter something like Longshot's power. I've also heard that Longshot's power doesn't backfire unless he tries to use it for something bad. It's supposed to only work when he's being heroish or doing something selfless, etc.
I agree on the strength and durability advantage, but I'd like to know if these two have ever fought. Or if Spidey has fought anyone with similar powers, like Domino. It would probably help Longshot's cause if they were fighting somewhere where his powers could give him more of a chance, like a major city (not NY, that just screws him over 😛 ) .