Tried and tasted both during my last holiday trip. My verdict? I love them both especially salted caramel from Ladurée and white truffle from Pierre Hermé.
But if I were to pick only one, then Ladurée will be it. Don't get me wrong, Pierre Hermé macarons are good too - their shells are chewy yet crispy at the same time but i love Ladurée's fillings more as they are not too sweet for my liking. :-)
Please excuse me now while I go and indulge myself with my fav salted caramel. SK just got back from his trip yesterday and bought me a box full of Ladurée that could last for a week! Yay!!