OO seems like more of a by-the-book place on reserve. I don't mean that in a bad way, but more of its a larger, less personal company. Many facets are more automatic, i.e. a computer deciding whether you'll be released early or not. At the last place I worked, driving a 1900, it was a much smaller more personal company and I think you'll agree that developing a good working relationship with schedulers was possible that allowed some give and take. Especially wrt commuting home on go-home day.
Given this, my reserve mantra is to play by the book, by ready to go or answer my phone on a RAP.... but never outside that. They can leave a message and I'll decide whether to call back or not. I don't give up my time off either. I would always at least check out what the assignment is (you can do so without acknowledging, I think with the button to print the pairing). If it ends up being beneficial to you (i.e. you finish earlier on the last day), then why not take it?