Muscle Memory costs 10 durability while one FS cycle will on average give you one ToT and a full CZ cycle. So in high end crafting MaMa+FS is almost always superior, unless you are using a rotation which doesn't need the extra 10 durability (which could occur if don't have enough SHII to cover the extra gap) This can occur in short rotations which have less hasty touches but stack up on extra CP for basic/precise touches (like 70/80 durability macros muscle memory is far superior).