Pros
I had a few different roles across the org over several years. The consulting side of the business would be familiar to any mid-career consultant. The junior experience IS much more intense, high-visibility, travel-bound and personally taxing than what you might find elsewhere. It's a challenge that will seriously boost your career if you can make it through. Because BTS has such a breadth of clients/industries, there is a lot of variability from project to project.
Cons
In the past few years BTS has begun to supplement its core training-consulting model with digital learning, and has built up a rather large tech division in India. My time with the digital side was mostly characterized by the friction between a sales-driven consulting company led by people-pleasing account mangers and a (very much subservient) product development org attempting to work in Agile. The consulting business constantly sells new promises and new features that simply don't fit align with anything on the product roadmap. Planned out your next few sprints? Forget about all that; the New York office just sold a million dollar deal that requires something that doesn't exist at all yet, so that now takes priority. And.. what's that? The Chicago office just did the same, and now that is being dictated as the new top priority? This is not a product-led company; product development is treated like a service for the consulting business to call on at any time. So if you're interested in BTS for a digital role I could not recommend it.