Lindy and I are both on the smallish side (but not as small as we used to be). She is 5 ' and I am 5'7". We found the bed on the 17b so comfortable, that we ditched the queen size bed in our home and replaced it with a full size bed. It turns out there is plenty of room for us, makes our bed room feel more spacious, and we can find each other -- as opposed to those times we stay in a hotel with a king size bed, and have to send out a search party in the morning to make sure we both still there.
As for climbing over each other, that seems to work out just fine.