cpan or perl -MCPAN ?


I'm using Linux for some perl play.

Which method is considered better - using cpan as a command at the
command line or using 'perl -MCPAN -e ..'' ?

Does using CPAN by either method above ensure the latest version of
any given module or does it give the latest module for the particular
version of Perl?.

I'm running 5.8 and am aware 5.10 is out there - I would hope modules
would fall gracefully back to 5.8.8 but am aware this might not happen
for some modules.