I think with L.A Noire it was mostly how awesome the trailers looked, compared to how the gameplay actually was, as a game it was great of course, but as a franchise, they could have done more to launch it. Have you played the remastered version of San Andreas? it's quite comical and extremely nostalgic.
Yeah definitely, your laptop should be able to handle the game engine, I don't think online servers run for it anymore, however it really doesn't matter, I'd strongly reccomend getting the DLC packs too, just for the added awesomeness.