I am just starting out with Asterisk and have installed Asterisk 1.2 on CentOS 5.5 from the atrpms repository.
I now have a working system and am connected to an IAX trunk provider. I am able to make incoming and outgoing calls.
I have not yet added any extras like on-hold messages or voice mail.
It appears from the upgrade.txt that using my configuration files on Asterisk 1.4 in the future should be a simple thing to do.
At this early stage I have the alternative to remove Asterisk 1.2 and install Asterisk 1.4 from source and use that instead.
Given the overhead of managing updates outside of the repositories, what benefits and new features would Asterisk 1.4 provide to make this worthwhile?
In short, should I upgrade?
I think you should.
In our use, Asterisk 1.4 has proven to be a lot more stable, have fewer bugs and also, is still supported.
Under your configuration the upgrade should be easy, and you start building your IP PBX using stable ground. If you try to add features to your current 1.2 installation you will most probabbly hit some bug or security related issue that you would have to backport manually.