I naturally tend to go towards stop-losses rather than stop-wins. It's silly to "double up and go" because as another said, what's the difference the next day? Yeah sometimes if I'm up massively at a table I might leave but generally I'm ok with staying and playing (live or online) if I'm playing well. And yes I've def had sessions where I've run well then suddenly keep getting beat and profit is gone.
However that's ok long run. I'd rather leave after my stop loss than lock in a profit. It's poker, not a slot machine. It can sting to grind for hours see a nice stack then run into a few
hands and see your stack go from + to - real quick. But that could happen the next time you play anyways.
Better to have a stop loss (for me live it's 2 buy ins, and online a little wider like 3-4 buy ins and that for me means actual, not profit lost) than a stop win.
And to complicate things we also must consider mental game. Sometimes you just feel it's time to go or you're up and feel you need to stay...so sometimes I stay when up or down and sometimes it's worth it and other times it stings but I walk away.
Set a stop-loss and at the same time consider your mental state throughout play, as these two variables come together you'll find what works for you.