Would vs Used to

1). Used to can refer to repeated actions and events in the past, in the same way as would.

e.g

Sometimes he used to bring me little presents without saying why.

Sometimes he would bring me little presents without saying why.

2). Only used to, not would can refer to past states.

e.g

I used to have an old Rolls-Royce. (NOT - I would have an old Rolls-Royce.)

3). We use used to, not would, to talk about regular and important habitual behaviour.

e.g

I used to smoke. (NOT- I would smoke.)