I must say there is nothing better to wake up to the gummy smile of your LO, be it 5am when their crying in their room waiting to be feed. Generally I'm not in the best of moods tired and with a sore back, but as soon as I lean over Otis's cot and see him smiling at me I just melt! The same goes for when he's in our bed in the early morning and I hear him cooing away and open my eyes to see him smiling!
In terms of what's best I guess that's really up to the individual, my sister had her son sleeping in her bed for well over a year - on and off that is. Personally I don't think there is a right or wrong.