If you're interested in this question, you should check out
this report from 2011 commissioned by FIRST. In particular, from page 7 of the report:
"FRC members were more likely to
report increases in their interest in science and technology (97% vs. 95%), in their plans
to take science or math courses (90% vs. 86%) and in their interest in going to college (92%
vs. 87%). FRC team members were also more likely to report learning about key values,
including Gracious Professionalism (96% vs. 90%) and volunteering in the community (83%
vs. 74%). Team leaders reported a similar set of gains. FTC team members, on the other
hand, were substantially more likely to report an increased interest in computer
programming (91% vs. 78%) and were as likely as FRC participants to report that they were
interested in science and engineering careers (85% vs. 83%). FTC and FRC team
members were also equally likely to report gains on questions related to life and workplace
skills (FRC members were more likely to report gains in communications and cooperation
skills, but there were no significant differences between program on the responses to the
other skill questions). "
The numbers are pretty darn similar, showing the very similar benefits of both programs, IMHO.