Upgrading Sleep Number i8 - Opinions Requested

[LowHanger]

My wife (5’8", 130lbs, back-sleeper exclusively) and I (6’2", 210lbs, sleeps on all four sides, no real preference) have an i8 split-king, purchased in 2014. I don’t really have any complaints, but my wife isn’t very happy with the bed so I’d like to do something to help her with her comfort. Her main complaints are that she doesn’t feel comfortable on the bed - can’t get much more out of her than that unfortunately. Have tried all of the sleep-number air pressure settings, none of which have unlocked comfort for her.

For those that don’t know, this bed is constructed with a 3" foam comfort layer which is zipped in to the top layer of the mattress cover - see pic here for reference:

I think the foam layer is pretty well shot at this time, so I’m going to replace that. While I’m at this, I’m going to replace the entire mattress cover. Sleep number quoted a price of $370 for a new cover - that doesn’t sound like a bad price to me, but if you’re aware of better and/or more affordable options, please let me know. I’m assuming (but haven’t yet confirmed) everything else in the mattress (foam border walls, foam base pad, air bladders, etc) is fine and I’ll be reusing them.

The main questions I have is with regard to the replacement foam comfort layer. I’m pretty sure I’m going to go with a 3" Talalay latex layer instead of the 3" foam that’s in there now. Here’s the main things I’m still pondering:

1. Since it’s a split-king bed, should I purchase a king mattress and cut it to fit the split-king mattress, or should I just purchase two twin-XL latex layers? As I understand it the king will be glued anyway as they don’t have king-sized molds - not sure that makes any difference though. I’m thinking I won’t notice any gap in the center of the bed if I go with the two twin-xl setup, but would welcome your thoughts on the subject.

2. What firmness/density would you recommend (I know, personal preference reigns supreme here)? If I get the two twin-XL setup I’m thinking of getting one plush (20-24 ILD) and one medium (25-29 ILD) and let her pick which one she prefers - if I go with a single king size mattress I’ll probably just go middle-of-the-road and get a medium.

3. I’d like to get a high-quality mattress cover for this whole setup to (a) protect the mattress, and (b) ideally, keep us both cooler (perhaps a wool cover?). Being a split-top I know I have limited options, but would be willing to go with a non-split cover as frankly we don’t use the split-top feature. Any recommendations? The whole mattress height is about 12" top to bottom.

Thanks for reading, and I look forward to any/all responses.

[Arizona_Premium]

Since she can’t really define what she thinks she needs I like your idea of getting both the 20-24 and 25-29 ILDs. You can either order a dual firmness King topper from us and either we will bond the 2 together or you can tell us to leave the 2 pieces unbonded. Use our Comment Section on the order form to request the dual firmness and/or bonding or not. We can also provide a King cover to hold both sides together but you will have a firm center but you won’t have any gap. You can always call if you have any questions. 888-773-7326

[Hiattech]

I’m not sure on the topper, but I personally would hesitate on a split king. We got ours (not sleep number) almost 10 years ago because I didn’t want to sleep at an incline while my wife does. She also likes a softer mattress. We were both heavier at the time. As time went on, I tried the incline. I liked it so we ended up at the same incline. I’ve slowly come to decide that I don’t mind the same softness level as her. However, the thing that we really don’t like about a split king is that gap in the middle. It’s very noticable. The bed likes to slide apart. We like to start our night spooning and the gap makes it difficult because of the sliding. There’s a middle fill strip you can buy but you want to put that under all the padding and buy regular king sheets and such. That’s our experience anyway.