I bought the Split King and it works very well with my new sleep number bed.  I love the preset settings and it's not too loud.  The USB ports are a nice touch and it was easy to put together. My only complaint is that I bought the Split King but found out when it arrived in 2 Twin XL boxes that there is no difference between the two.  This isn't a big deal for functional purposes, but financially when I purchased the bed frame, 2 Twin XLs were actually cheaper than the Split King by $100.  This doesn't make much sense and I haven't been able to reach the manufacturer yet.