I think you can live lucid dreams and have big feeling about them just when they happen. When you wake up you will remember them but without big feelings. Just like real life memories you remember them with fuzziness. This is why you want to upgrade your dream recall, it will enhance it but it wont make it like the experience itself.
And for the time, no one know how much you spend in the dream world. But, there are experienced lucid dreamers that can dream about 1.5 hour and they know that because they make WILD and the lucid dream start instantly and see the time before and after. But in the same time there is a phenomena called time dillatation where the dream seem like it is years and years long, but in reality it can't be more than 2hours.