Split King Adjustable Mattress

We purchased the split king, two twin XL, mattresses. Both are independently adjustable for firmness. Purchasing, delivery, and setup was easy. We purchased the adjustable bases separately on amazon, as it was a lot cheaper this way. Initially I thought we had purchased a flex top king and was a little surprised when the mattresses arrived in separate boxes. I contacted support, which is very responsive, and noted my concern of two separate mattresses. They suggested we try it out as there is a 180 day return policy. We slept on the mattresses for 45 days, the minimum required trial period and noticed a significant improvement with our sleep. But we could not get past the gap between the two mattresses. I purchased a binding pad and a gap filler, which worked fairly well but required constant tightening and adjusting the gap filler. I called support and expressed my concerns and they are going to replace the two twin XL mattresses with a king flex head. We will still be able to adjust the head independently and the firmness of each side but the foot will have to be adjusted together. The bases I purchased on amazon came with a sync box for the foot adjustment as that is what I thought I ordered. So far we found the mattresses are very comfortable, adjustable for firmness and head and foot level, and sleeps very cool. I would recommend iSense to anyone. I will update when our new king flex head arrives and we sleep on it for a few months.