Hi, we transferred our DS gradually from nest to cot, starting at 8 months. We started with lots of co-sleeping so he could get used to lying flat (he'd co-slept a little in the past anyway), and he was very comfortable in our bed (he always tried to snuggle up to us, as I guess he was used to feeling snuggled in the Amby) so I also started putting him down for day time naps flat on our bed (with bed guards).
Still loads of crying every time he was put in the cot (though if he fell asleep feeding or was very drowsy e.g. after falling asleep in car seat, I'd put him straight in cot and he wouldnt' notice until he woke up).
Then after he was very good at falling asleep on our bed on his own, I put him down in cot for daytime naps, and he suddenly didn't mind one day... he went to sleep happily on his own. I give him just two cot toys and they are always the same. I started doing this when he was still in the bed.
All this time I kept trying to put him down at night in the cot, transferring him to the bed if he got very upset (I didn't want to make the cot a 'miserable' place). There was a period of about three weeks where he'd nap happily in the day in the cot but scream as soon as he was put in it at night.
Then gradually, he spent longer and longer in the cot without waking up, and now (at 9.5 months) I can leave him to go to sleep in the cot in the evening too. He does move around it, and tries to curl himself up on his side, like in the Amby (curled up, not on side that is). He's in a sleeping bag, which helps gives a snug feeling.
The key for me was packing up the Amby and hiding it away, so I wasn't tempted to use it again! Our friends are taking it even more gradually and stopped any bouncing to sleep before attempting cot, so at least their baby could fall asleep without being bounced.
You could also try hanging something from the ceiling, so it looks more like the snug cover of the Amby when your baby looks up.