The main differences between educational software and retail are twofold.
First, as stated, only the original purchaser can upgrade as an educator or student. In some cases the software manufacturer doesn't allow upgrades at all, you have to buy the newer ed version.
Second, the software application is usually fully featured and using it would be not different from using retail versions. However, extra plugins, demos, images, templates, tutorials, etc. are often left out. Again it depends on the particular manufacturer as to how much is not included, in fact sometimes it is identical to retail.
I've bought several ed applications as a teacher and all have performed with no features crippled. The only way you know it's an ed version is in the splash screen on some where there is a notation to that effect and a warning that it is only to be used by authorized personnel.
