I was a leader for TBB a few years ago and while I saw a different side of the program than the participants did, I was still a hugely important experience for me and one that still informs many of my decisions and interests currently. I've also led and had experience with a few other student travel organizations and while I know many of them run valuable programs, TBB's are special. Here's a few reasons why:
1) The quality of the program. The program is more than a curriculum, more than an itinerary, more than work projects, more than a set of goals - though all of these things are addressed with such thoroughness and intentionality you'd think there'd have to be a staff of 15 people designing this course and not just the handful of exceptional individuals who do it. The curriculum entails a college-level reading list with accompanying seminars and creative projects that changes the ways students are used to interacting with 'academic' material. Readings can cover both classics and the latest literature on a given problem. Moreover, traveling with laptops, kindles, and academically experienced leaders, the group always has the option of modifying the curriculum to meet student interests or address current issues. The 'work projects' can sometimes seem fruitless to students - as there might not be a new school to marvel at by the end of your stay in wherever - but they are more focused on exploring an issue than they are producing a tangible result. The program is perfect for students who are interested in learning.
2) The comprehensiveness. Virtually nothing is excluded from TBBs scope. Students are given the opportunity to explore every aspect of themselves, internal and external, personal and social, academic and physical, their personalities at work and on vacation. The range of geographic locations (city to forest) also vary widely and students are able to explore across environments and issues - as well as simply experience life abroad in some of its many settings. For example, too often Gap Years feature nothing but the exotic jungle of Bali or wherever, forgetting that the vast majority of people in the world are dealing with issues of urbanization more immediately than they are with issues of the destruction of coral reefs. Not that reefs aren't cool, but you get my point!
3) The change entailed. This program is hard, long, not for the weak or those who just want something - anything - besides school. This means, however, that students can emerge from the program rather differently than they entered. After returning from a summer or even semester abroad, it is easy to fall back into the same habits and worldviews that you had before you left because you didn't spent all that much time breaking or at least reconsidering these assumptions. TBB is long and intensive enough to develop a significant change in personality. I think nearly half the students on our trip changed the university and/or major by the time they finished TBB. The people who come out of this program - students and leaders both - are very different than they people who went in.
The only downside of TBB is the price - though it has dropped significantly in recent years. Moreover, the TBB staff is committed to helping students fundraise for their own trip - a valuable skill to acquire at such a young age. This should also help attract a great diversity of participants, which would also benefit the program greatly.
From it's own side, TBB is an incredible program deserving of almost any student. A better question to ask yourself is: are you deserving of TBB?