Pros
RE/MAX allows agents to have their own private email addresses (Gmail for example) and lets you keep all of your leads. It's a great company for agents producing at a high level, because while there are fees, if you make enough, you can set it up so that you pay a higher fee, but keep 95% of your commission. Once you cross a certain level of sales... even with the higher monthly fee, only having to pay the company the 5% sales commission can become a WAY better deal. You can also pay a smaller fee and a higher % of commission (depends on your production level and preference). Agents are allowed to be very independent - they can choose how they want to run their business and they earn from what they produce.
Cons
Not a company to come and expect leads. All offices are independently run, so they are not all created equal. Be sure that you meet with the managing broker/owner and that you really like what they are about and the culture they create in their specific office. Monthly fees - you pay for what you get, I suppose, but if you are not really using the office, your broker and associates in the office, the famous / most highly recognized agency name, and/or the online tools, or training (if your broker/owner provides, some may prefer to pay less.