We have been using tracks now for over 10 years.
1) When done right the tracks system are easy to make and easy to fix if something goes wrong.
2) tank system has a better chance of having a lower center of gravity than the wheels system. ours CG is about 3" off the ground
3) when it comes to pushing other robots I would say we are in the top 5% in doing this. We have not come across any wheel robot that could push us in a pushing contest but we also use 4 motor drive system.
4) very costly $200+ per track $140+ for pulleys
5) tracks can overcome any obstructions.
6) under extreme stress track will rip even with the best tracks. ( but robot can still move without tracks.)
7) We have worked with Breco Flex for the past 10 years and had some good tracks come out of there company.
8) go to our web site to see all of our past robots and see the track system
http://www.valleytech.k12.ma.us/robo...photos2004.htm