Thoughts on Breaking Bad - Face Off and S5 episode Live & Die

I finished my Breaking Bad marathon and everyone was right, BB is the best television series ever. Nothing I've ever watched comes close to it. It's flawless.
But the subject matter is admittedly difficult.

Currently debating something my co-worker stated today, that maybe BB should have ended in S4, that finale would have worked beautifully as a series finale. (And as an aside, it may have been meant as a possible series finale - since renewal was up in the air for a bit. AMC was struggling to afford MAD MEN and Walking Dead, two expensive series. BB is actually better than both, no question about it.) But - S4 was a work of beauty. Not sure S5 will live up to it...sometimes drawing out a series too long, loses something. Which begs the question, when should tv shows end?

I've debated similar questions about shows such as Buffy, MASH, BSG, ER, The West Wing,
Happy Days...etc. Would it have been better if they'd ended earlier? I don't know.
I honestly don't. I can argue it three ways from Sunday and still can't tell you.
Oh well, they didn't. So..c'est la vie or que sera sera...as the case may be.

Regarding Breaking Bad - was a bit upset that something I was worried about happened.
( spoilers for BB S4 and BB S5 first episode - Oh God, Walt, what did you do? )