I hunted mule deer with him 10 years ago and it was terrible. My comment isn't based on just one factor related to the hunt - it is based on 'everything' to do with the hunt.
Four US strangers were brought together by Carlos Hermosillo, and we each shared the same atrocious experiences.
Absolutely nothing he promised came true. From the poor camp, to the cook (a 19 yr. old with filthy hands); to the guides (good men, however without a clue about hunting) to over-hunted ranches (four experienced hunters x five days hunting = one deer sighted); to one vehicle for four hunters (some of us got picked up after 8pm each day) etc., etc., it was all terrible.
My understanding is that our experience was not the exception, it was typical.
I read here that at least one hunter had a good experience with Hermosillo, and I am happy for that hunter.
However, I continued going back to Sonora to hunt for a decade more (certainly not with Hermosillo). During that time I had ample opportunity to learn the ropes there - meeting people, learning the ranches, etc. Good outfitters (Mexican & US) can be found in Sonora. However, you have to be careful.
And regardless of the man here in MM who had a good experience with Carlos Hermosillo, I wouldn't consider hunting with him ever again, and would never recommend him.