Disabled vet and disabled spouse purchased this I8 bed in March 2015 and have had continuous problems with this gap and slant of mattress on both sides. We paid over $7,019.96 for this bed yet it is unbearable to sleep in at night. I contacted Customer Service and they state Sleep Number finds a 6" gap acceptable on these beds. So if you want to sleep on a slant and can use only 1/2 of the twin side of a bed then this is the bed for you. We own 3 Sleep Number beds and this is the worst of all. Military disabled vet has breathing issues as well as spouse so this bed was supposed answer to these issues BUT it does not come with a warning that your bed will separate and slant to the center so both partners are miserable. I find this unacceptable practice for Sleep Number Company to know there was a design problem from the beginning of marketing since I was told they tested a strap to hold bed together but found it tore open so that was removed and it is their choice to market a bed with severe issues to sleeping a conducive night of rest. I sleep most nights in our living room on couch since this bed causes me so much back pain fighting to stay in a position hugging the edge of bed.
Note: Sleep Number took down this first review of this bed so we will see if they only allow good reviews to be written on site.