Silkrose, I love your approach & attitude. Where are you?
While I don't like clockwatchers, on the other hand I'd never abuse the generosity of someone who doesn't mind going over a few minutes.
Of course I'll always take quality over quantity. So if it's a bit short but a fantastic session, I don't mind.
This reminds me of a People's Court tv show where the wedding couple didn't want to pay the band because:
1. They sucked
2. They didn't play long enough!
That's like Woody Allen in Love & Death who said that life is like a bad restaurant: bad food & such small portions.