Unless you want to go looking for an unofficial beta version, it's the only choice. 4.2.2.196 was the last official version after 4.2.2.176 and before 4.5.0.138. Once Verizon released 4.5.0.138, they took 4.2.2.196 off their site. I don't recommend unofficial beta releases. Usually they are not officially released because they have problems.
4.5.0.138 is not perfect. Everytime I reboot my 8830, BBM thinks I have a new device and wants to reinitialize pins. And earlier today my 8830 rebooted spontaneously while I was typing a message. So there are clearly some issues with 4.5.0.138.