I can't speak for my team as a whole but I personally use both. I feel you should use whatever is most comfortable for you. It shouldn't be a problem if you have to give someone else dimensions as long as they know which system you used. The reason I use both is because being from the U.S. I naturally use ANSI since that is most used here, but the injection molding robot company I work for (thanks to my involvement in FIRST) is based in Austria and thier stuff is all metric. To be honest, even though I've grown up with ANSI, once you learn metric it's much easier since it's based on "10". It's great if you don't have a calculator handy and wind up doing calculations in your head. It's also good to have some knowledge of the metric system in case FIRST decides to hold a national competition in Canada!
