I have the matchup against Z/S listed as 6-4, G&W's favor, recommended to stay Sheik at all times.
G&W outprioritizes Sheik and KOs her pretty early too, plus he's really hard to gimp with his above average recovery. Tiltlock gets damage up quick and if you get tipper usmashed (probably through ftilt setup) it could be bad for you. Chain can also make things difficult MAYBE; I haven't looked into this part so much yet.
Mostly the problem is that Sheik has to work with lower priority until G&W reaches like 150% or so and then use an unstaled dsmash or nair. Or abuse ftilt so much that she can combo ftilt usmash consistently. Too bad G&W's aerials can eat right through ftilt.
G&W outprioritizes Sheik and KOs her pretty early too, plus he's really hard to gimp with his above average recovery. Tiltlock gets damage up quick and if you get tipper usmashed (probably through ftilt setup) it could be bad for you. Chain can also make things difficult MAYBE; I haven't looked into this part so much yet.
Mostly the problem is that Sheik has to work with lower priority until G&W reaches like 150% or so and then use an unstaled dsmash or nair. Or abuse ftilt so much that she can combo ftilt usmash consistently. Too bad G&W's aerials can eat right through ftilt.