Well, I guess both sides of the coin have a few cons/pros, while "throwing code at a debugger", even if it hasn't been thought through all that well before hand, theoretically sounds like bad practice, having your variable contents, etc. given to you by a debugger, still in essence helps you better understand and think through your code.

Personally, I never used a debugger in Perl, I never could quite figure them out, so I ended up littering my code with print statements like

if (logic = $whatIthoughtitdid) {
    print "Entered into 1st if statement";
[download]

and also following every instance of strings/arrays by print statements giving their contents to me for the umteenth millionth time.

So, whether you think long and hard about your code before hand, or you have an epiphany after the debugger shows you your mistakes, you're still learning what your mistakes were, so once again, the Perl hacker just can't seem to avoid progression.