Iv'e bought "my little bed" and it lies in between DH and I in bed. It's got hard sides, but low (about 15 cm). That way I can have my hand on bub, and just pick bub up to feed and put next to me, but there is no way anyone can roll onto the baby. We do have a king size bed, so there's room, but it's not that wide anyway (the baby bed) and I always felt afraid last time with DD2 that DH would roll on her.
This also has a velcro thing that is good for keeping baby; on their back. xo