Boma is our favorite meal anytime, anywhere. I don't agree about the "sweet" taste in the food. Cinnamon isn't sweet, it's savory, unless you add sugar to it. We love Boma and it always gets my vote.
We've eaten at San Angel Inn 3 times, and every time we say never again. It's not the food- we love the food, it's NOT tex-mex which is what makes it so fascinating. Our problem with San Angel Inn is the personnel. Every single time we eat there, we feel like our presence is inconveniencing the staff... Like what a great restaurant we could be if only the customers weren't around. I never get the feeling that patrons are welcomed, that the staff is glad to see you or cares if you like your meal or not. It's more of a "what'll it be, here it is, eat it and get out" feeling! We go for the food... and certainly not on every trip (unlike Boma, where we sometimes go twice in a trip), because the staff is just so unfriendly and ungracious (if there is such a word) that it makes for a generally unsettling experience!