I've worked for multiple companies during my career, and Monterrey has been the best by far in all regards, BUT that doesn't mean they couldn't get better.
Much like any job, entry level sucks, but Monterrey is the type of company that if you work for them, they'll work for you... It is very easy to be just another face in the crowd, and it is almost equally as easy to be a name the owner knows personally; they have some large, high profile accounts, but they are still a small family business. They're management team is so so... there were a few good managers if you work at a regular post, but dealing with the people in what they called "events" was usually a hassle, a hassle that may or may not be worth it depending on the event you're trying to work. Every time you see the owner though he's usually angry at someone, yelling, or trying really hard to not yell and fake a smile; he seems like an tool, but I probably would be too if I owned the place.
Bottom line if you want to make money here get your PERC card, and try and get at a regular post, and do events as needed. Learn to play the game with the managers, they do have their favorites, and if you're in with one it seems the others start to fight over you...lol... its almost flattering. You will not make a decent living just doing events, unless you are an off duty cop making a high rate to ultimately do nothing from what I can see.