I participated in the RC program. There were no issues and some really good things about the new version. I really like how much better it is integrated with NPM 10.7. I did have to upgrade NPM from 10.6 to 10.7 before I could install NCM 7.3.
Database merge was seamless. My only issue was partway through the NCM upgrade it wanted to reboot. I didn't expect that. I asked support before I proceeded. I ended up allowing the reboot and the install just picked up where it left off. I wasn't sure it would since I was RDP'ed into the server.