3.3x and 3.5x all connect to the same network with the same users, 3.54 is just 3.53 with a few bug fixes and a new library, the networking parts are all the same and it uses the same network
the only major difference is that 3.54 has a new library that can make it easier to manage your shares, other than that it's all the same except for a few bug fixes (the bug fixes are the main reason that it is the recommended version)
and btw you don't need to uninstall 3.53 first, just replace it