Fluval 304 vs 305?

Hi,
Does anyone have both of these models or have actually seen them side
by side?
I have heard a few things...that people visually thought they were
pretty much the same but could someone tell me more precisely the
differences?

I can get the 05 series for about 20% more, but is it worth it? That's
the big question.
Another thing...I have never used a canister filter, do I need to be
worried about a major water accident from a broken connection?

Thanks!
-joe