I teach Autocad classes, CAD. So I should use an Autocad program when it first came out back in the 80s? Autocad update there programs every year. I have no problem using a program that is 5-6 years old. Beyond that there are too many differences. A classroom site Lic. cost around $15,000 dollars. Money that my school does not have. I retire in 6 years, I'll be betting that I will be using the same program that I am today 6 years from now. The program that I have now is 2 years old. It isn't cheap to run my program. One other thing the kids are learning a skill that 99% of adults do not know how to do.