Features that look easy to implement and are not a big deal can turn out to be massive problems and require a large amount of code to actually pull of. I would,

Features that look easy to implement and are not a big deal can turn out to be massive problems and require a large amount of code to actually pull of. I would, in some cases, count responsiveness to be one of those things. Stuff like that may seem like 5% of the functionality but actually makes up a large chunk of the code. This is why you must always have feature parity if you really want to compare code size.