Bring the air mattress. That will give you another option if sleeping with the kids does not work out. Our youngest moves around so much there is no way to sleep with him. Those big thick air mattresses are often more comfortable than a hotel bed so be sure to check it our prior to giving it to one of the kids! The air mattresses fit regular twin sheets so be sure to bring a top and bottom sheet.
I agree 100%. In May we stayed at a hotel the had two full size beds. The first night no one got any sleep. DH refuses to sleep with the boys since they move around and my youngest kept on kicking my oldest. The next morning we went to Bed Bath and Beyond and got a Aerobed twin size for $59.00 less 20% ( I had a coupon). It was the best investment made. DS4 slept on it and DS9 sleep with me. He moves but only a 1/4 as much as DS4, plus he doesn't flip upside down, turn sideways, etc. DS4 wants to be so close to me and DS 9 likes his space. We used the bed again last week during our quick trip to NC and we are bringing it to Disney when we stay at CSR. Although we have two rooms, my mom and DS 9 are in one and DH, DS4 and I are in another I plan on using the Aerobed for DS4 and DH and I can each have our own bed.