Pros
If you decide to get your masters in ABA through the program they provide, the program itself is free. There is a lot of opportunity to be promoted, many opportunities to gain new experiences, and learning is very hands-on. If you're committed to a career in ABA, this is definitely the place to start, as you will get the best experience possible.
Cons
The master's program feels a bit "cult"ish. Your instructors and supervisors are all employed by NECC, the classes you take are hosted at the central facility, and nearly all thesis participants are students at NECC. You spend a lot of hours working and being at the central facility; sometimes it feels as though you never leave. The pay is nowhere near what it should be for the nature of the work and the actual number of hours you spend working.