it depends which part of mexico. i hated where i had to stay in mexico for the weekend. because you could here gun shots and night and police sirens and the hotel i stayed in smelled really bad.
well if its monsters higher level or same level as you, you might need someone with you. but you're more likely to get more crates solo because the more people there are, not just in a group, but the whole area, the less chance of getting a rare crate