I would just like to add my two pennies, as a relatively recent agent in NY and working for Sotheby's. My experience getting started as a part time agent, Working as a Project Manager during the day building high-rises in NYC and currently a 114 unit apartment building in Westchester, I find myself only going into the office to make balloons for open houses and print off color copies. Sometime I would need to do phone duty, but that was rare, given my schedule. My mentoring, or the place I would ask questions and get the most responsive help from was a long time friend who connected me with the interview. None on my deals so far have come from the millions of dollars Sotheby's spends on branding and market share. My deals have come from my network. Through personal friends and BP! When you are starting out, its the people you know, the people they know and the people you will meet that will be your deals. Granted, I love throwing the Sotheby's name around, It IS very prestigious, but at the end of the day, the high end $10M+ listings may find international buyers easier but I think as long as you have a good connection with SOMEONE where you work, you will have every ability to be an amazing Real Estate Salesperson, at whatever level you chose.
That all being said, I have started to learn about EXP and at this point, I can not find another brokerage that offers as much as EXP does in the way of compensation for the time and work you put into your craft. I have been meeting people left and right at different agencies, who all have the next best thing, Exit, KW, Weichert, ... the list goes on. It seems as though, all of these brokerages are adapting to the new reality of the current technological world we live in. Many are starting to offer caps and 100% compensation, commissions based on recruiting efforts, etc. but in the research I have done, it seems reactionary as opposed to being designed from the very beginning. I think a suitable analogy is electric cars, its the difference between ford coming out with an electric car that is basically a ford festiva with bunch of batteries stuffed in the front seats and the gas fill spout converted for a 110v socket compared to a tesla which was designed from the ground up to function as a sleek electric vehicle that is sexy and beats all records. When the first roadster rolled into the auto show and everyone was like, "whats that, it doesn't make sense, the other "gas" vehicles have much more research and years of testing, they'll never be replaced." They have been refining teslas at exponential rates and now the "old school" auto makers are not able to compete overall. I see EXP doing the same thing in the real estate industry. their business model seems to take the future of this business into account now, and its just a waiting game to when the old style will fall and at that point EXP will be so far ahead, nobody will be able to touch them.
VERY long story short. As many have said in this thread, talk to as many brokers and brokerages as possible, get their offers and compare them. Really know what its going to cost you to be with them. You are the asset, any Brokerage should be thrilled to have you a part of their team, and should want to educate you and help you to be as successful as possible. I would be happy as many people here have said to talk to you further, on the phone, through DM on here, on Facebook, in person, whatever medium you like best to discuss your options or questions.
If you find a better deal that EXP has, I would love to hear it! Please keep me in the loop!