What does vim-perl plugin do that "syntax on" doesn't? - perl

Question

I'm trying to get vim set up as an IDE for Perl. I'm using generic, text-based vim, not gvim.
I installed the "vim-perl" addon at https://github.com/vim-perl/vim-perl using the vim addon manager per the suggestion of someone else. At least I think it's installed but I don't notice any difference in how the file is processed.
First I installed the vim-addon-manager with Debian's package manager. Then I put the following code in my .vimrc file and reloaded it:
" put this line first in ~/.vimrc
set nocompatible | filetype indent plugin on | syn on
fun! SetupVAM()
let c = get(g:, 'vim_addon_manager', {})
let g:vim_addon_manager = c
let c.plugin_root_dir = expand('$HOME', 1) . '/.vim/vim-addons'
" Force your ~/.vim/after directory to be last in &rtp always:
" let g:vim_addon_manager.rtp_list_hook = 'vam#ForceUsersAfterDirectoriesToBeLast'
" most used options you may want to use:
" let c.log_to_buf = 1
" let c.auto_install = 0
let &rtp.=(empty(&rtp)?'':',').c.plugin_root_dir.'/vim-addon-manager'
if !isdirectory(c.plugin_root_dir.'/vim-addon-manager/autoload')
execute '!git clone --depth=1 git://github.com/MarcWeber/vim-addon-manager '
\ shellescape(c.plugin_root_dir.'/vim-addon-manager', 1)
endif
" This provides the VAMActivate command, you could be passing plugin names, too
call vam#ActivateAddons([], {})
endfun
all SetupVAM()
" ACTIVATING PLUGINS
" OPTION 1, use VAMActivate
VAMActivate github:vim-perl/vim-perl
" OPTION 2: use call vam#ActivateAddons
"call vam#ActivateAddons([vim-perl], {})
use <c-x><c-p> to complete plugin names
" OPTION 3: Create a file ~/.vim-srcipts putting a PLUGIN_NAME into each line
" See lazy loading plugins section in README.md for details
" call vam#Scripts('~/.vim-scripts', {'tag_regex': '.*'})
So what exactly is the vim-perl addon supposed to do for me? I can't find any good documenation anywhere.

Answer 1

At least parts of vim-perl are incorporated in the factory-default configuration of Vim; cp. $VIMRUNTIME/ftplugin/perl.vim and $VIMRUNTIME/syntax/perl.vim. By installing (and regularly upgrading) the plugin, you'll get:
a newer version of the scripts, with potential enhancements and bug fixes
some additional functionality (f.e. there's a syntax/mason.vim that's not yet in Vim itself)
If you regularly edit non-trivial Perl scripts, or use latest language features, installing vim-perl is worth contemplating. If you're just a casual programmer, I would wait until a real need arises.