I worked at Marx|Okubo Associates for less than a year
I came in with the goal of finding a way to transition from architecture and design to construction and management field. They really take chances on interns here. Having had minimal experience in... construction, I was surprised to be welcomed to the team (there was another intern who just finished her Freshman year). As with any job and internship, if you come in with no clear intentions, you will leave here empty handed.
Make sure you are clear (to yourself and to MO) of what your goals are; there are a ton of people who wants to help. Sandy made sure I got to work with other senior associates/VP and tag along MO's in-house MEP engineers. I got to work and interact with project coordinators who were super knowledgeable on the site and back in the office when we worked on PCAs together. Everyone here was super approachable. All you have to do is make sure you take advantage of these opportunities.
I was active during meetings and took initiatives to get to know the scope of the work. I asked questions and made suggestions. As an intern, it was a pleasant learning experience to feel as a part of the discussion.
When I first started, Sandy had implemented orientation activities, where each of the current employees were given a small task to get you checked-in (i.e. one person would show you how to set up printers, and another person would show you where the forms and request can be done). It was very structured and fun way to get to know everyone without doing those silly-summer-camp ice breakers.
I had minimal interactions with the Denver office, but they were really helpful and responsive when I needed to obtain my proof of employment from two solid years ago.
The hours are great. Having worked in Tokyo, Boston, and New York you do not need to pull late hours every single day. Sometimes, you do have to stay a little longer than usual but that happens depending on the scope of the projects and how the deadlines line up. Sandy does run MO in SF on strict schedule for our clients, and I appreciated it because that was one thing lacking in design and architecture firms.
I still keep in touch even after all these years so that should speak to the quality of people at MO.
Honestly, I didn't encounter any cons while interning at MO for one summer. I think the other reviewers complaints are more geared towards SF (traffic, high costs of living). than MO itself.