Alrighty... Mexidogs aren't technically a breed, but since there seems to be a lot of similarities between them....
Disclaimer: This is just what I've noticed with Cricket. They aren't necessarily guard dogs but they do alert you to strange noises and are super aware always of everything going on around them. For the most part they are very friendly, but can be a little reserved with strangers at first. They talk a lot... No they aren't constant barkers, but they will talk to you... Similar to how a husky talks.
They can figure anything out... Just yesterday Cricket opened up my friend's training bait bag while it was ON her and she didn't even notice it until Cricket was taking treats from the bag. They are problem solvers. I do wonder if part of that is because Cricket more than likely comes from generations and generations of primitive feral dogs who had to figure out how to survive.
They are VERY attentive to their handler and want to please though at the same time they still have that primitive independance thing going on. Cricket is more than ok with doing her own thing, but when she knows she is working she pays super close attention to me and is a total rock star.
I don't know if this is necessarily a mexidog thing, but Cricket also matured mentally super fast. People don't believe me when I tell them her age because more often than not she is really well behaved (aside from the occasional pulling issue that we are working through). Most of the time she trots right at my side and she can easily lay calm at my side even in tough distraction places. She tends to have that older wise dog ambience about her yet she still knows how to have her fun puppylike crazy moments.