Haven't read the other replys but when Darcy was 16months old she told us in no uncertain terms one day that she was never getting in that cot again!! It took me about a wwek to figure out why she wouldn't get in there. I borrowed a fold out bed and voila! Sleeping soundly again.
She went straight into a single ensemble. We didn't have a toddler bed and since they mainly use the cot mattress, Darcy was already nearly too long for that.
We have never used a bed rail - slack really but she hasn't ever fallen out except when she was mucking around (awake) on it.
No it didn't make bedtime harder, but she wanted to be in the bed - it wasn't me wanting her to be in it. She's never been a get out of bed and wander around kid. SHe is a night walker though, but we're adapted to that.