We were given a snuggle nest before out first. Great for sleep training DH to stay out of the middle of the bed while I was pregnant, waste of money once the babe was born. I found that co sleeping while nursing had the babe wanting to be head at boob height in the bed, the snuggle nest was just an awkward piece of plastic that got in the way. I also thought the ridged base made it too tippy in our bed, as in every time someone moved DD would get rolled around, which did not happen when she was directly on the mattress.
We just put our bed back up on the frame after having it low for awhile. DD was sleeping on a twin mattress on the floor next to us and DS is still in the bed with us. We bought bunk beds for the kids and have it in our room next to us (DD is not comfortable in her own room yet, sigh.) DD is happy on her top bunk, and the plan is to transition DS onto the bottom bunk before the babe gets here. He's chosen to nap there, so so far so good. At night he likes to be super close, kind of a new thing, so I'm really hoping it does not turn into a Daddy on the bottom bunk for awhile after the babe gets here. No matter what, babe and I get the king this time around.
Before anyone judges us, we are used to musical beds in our family. I have slept in the guest bed with a babe, on a queen mattress on the floor with a toddler next to DH in a king waterbed on the floor, on a mattress on the floor with a babe, next to big sister in her own bed, on a twin mattress on the floor with the kids in bed with DH, on the couch with the kids on an air mattress, etc... Some of the time all 4 of us were in the king together. DH has had our king size to himself for a good part of the last 8 years so this time around he knows he will be the one that gets to be moving beds to accommodate everyone getting a good night sleep. OK, maybe now you might want to judge us (ha ha ha).