Zonesleep mattress duel use

[icic]

We have at present the comfort mattress downstairs in a ocean. It’s not comfortable to sleep on.

So looking at a zone sleep mattress. We are unsure if just to get the standard zone sleep or the ultra. Wondering how comfortable the standard zonesleep or the ultra is on the comfort mattress or the ultra without the comfort mattress.

Is ultra really worth the extra ? Also we thought we could use the zone sleep in the pop top as well on the existing mattress if not sleeping downstiatds, it’s wider than the downstairs by 6cm, does that work well and is the 6 cm an issue ?