I am upgrading my SA 4500 SA 4500 from 7.02 to 7.1R3 to add mobile support to platform / Any issues I should know about ?
You could go through the Release Notes at http://download.juniper.net/software/ive/releases/7.x/7.1/b18671/j-sa-sslvpn-7.1R3-releasenotes.pdf to check for any known issues that may affect your environment.
if you have any desktop client users, they will be upgraded when they connect again; otherwise, nothing to watch out.