postgres source code installation vs rpm based installation

Hello Experts,

I have couple of questions on postgres installation.

1. which way of installation is better ? source code or rpm based ?

2. for instance , If we need to install same version postgres on multiple times on same server. how do we need to handle this with rpm ?

3. If I go with source code installation, in case we need to upgrade OS(6 to 7) , do we need to recompile existing postgres binaries ?

kindly share your experience.