Large franchises can sometimes offer more leads because they tend to have a more recognizable name. Training like the ones offered by Keller Williams and Century 21 are often very organized. There are some franchises who are still very unorganized and lack in training.
Some of the smaller places in town are doing very well. They sometimes offer a closer-knit group of people who all help each other. The brokers give more 1-1 attention and you have a chance to be very successful by leveraging off your other teammates.
The main thing is to ask what type of support you will receive, whether the broker has written policy manuals, and what type of ongoing training they provide. Some also aren't members of their local chamber of commerce, so ask about this as well. Being a member of the chamber sometimes helps with getting relocation referrals.