Here's another disadvantage of style #1 - what happens if you have name reuse? For example, you have a @foo that's used throughout the file. Only, in one place, it means one thing and somewhere else it means something else.
Actually, I see that as an advantage of style 1. Say you have a @foo, and it's used at different places, but in the same lexical scope. If you declare it close to where it's first used, you'll get annoying warnings that you redeclare a variable (I hated that warning when it was first introduced - it was introduced before, or at the same time that
foreach my $var (LIST) was allowed). If you declare all your variables at the top, you see you have a conflict the second time you try to declare @foo, and can pick another name.
Abigail