L.C.
With my first child I had a bissinet and hated it. I could not see my baby girl while laying down in bed, I also could not easily put my hand in there to soothe her if need be. I had to physically sit up.
With my second child I have the co-sleeper and I love it. The lowered ledge that goes along the bed is great. I often fall asleep while watching him (whether he is awake or asleep.) I can also put my hand on his chest and soothe him while I am still laying down. The co-sleeper has done wonders for me in getting more sleep. I don't have sit up in bed as much to help my child.
I cannot speak for the "Amby" but I really recommend the co-sleeper.