I didn't hear about it really until DD was already aware of Santa, and she remembers EVERYTHING!! We already had a fabric advent calendar that my Mum had made, and she gets a chocolate figure every day and something else every day too (a free colouring sheet from the net, a promise of an outing, a suggestion for a craft project, a reminder that today is the day to tidy her room, and occasionally a small toy or mini jigsaw). It's not actually that much work (I have a list of ideas which is a lot longer than 24, plenty of printables, and DD is also happy to laugh at me the odd time she has to remind me to fill it in the morning rather than me having done it the night before - she has always known Calendar was me).
However, I like the idea of the elves. So I am holding on to the ideas I have gotten since I first heard about them, with the plan that when DD is no longer a believer in Santa, the Elves will arrive.
We will always do stockings (my grown up siblings who sleep "at home" on Christmas Eve still have to put theirs out for Dad to fill with sweets, fruit and a book - the change he made when I got too old as the eldest, but with a 10 year gap to the youngest, I could not suddenly get nothing!) - but I intend that DH and I will get one as well then and we can all be involved in filling them.
And I think that the mischief that the Elves get up to will be something that DD will be interested and excited in. She is another Christmas Nut (like me) - her birthday is Boxing Day, so it is an important time of the year for her. And routines and traditions are also important to her, so changing things are ok once there is some form of continuity. So I think it will go down well in maybe 2-3 years time.