We went with Yimnah. She was awesome. We pride ourselves in our ability to navigate new and unfamiliar cultures and countries. And our Spanish isn't terrible. Definitely not fluent, but we know enough to ask basic questions and understand answers. La Merced, however, was absolute chaos, even when we tried to visit by ourselves after our tour with Yimnah. We left after and hour without having found any of the places she led us to. I can't recommend this tour enough. And, again, Yimnah was rad. Knowledgeable, easy going, a good sense of humor, and just a cool human.