Sealy Posturepedic® Titanium Dsi Series launched in 2011 is the first Sealy® mattress line with individually incased coils. It dramatically improved motion transfer and bounciness of Sealy Posturepedic® mattresses. D in Dsi means that spring works in two stages or as Sealy calls it - a dual stage conforming support. Sealy markets these springs as made out of Titanium alloy, but they are actually steel spring with a miniscule amount of titanium. Dsi Series also feature memory foam CoreSupport™ Center as an extra support in the central third of the mattress. More expensive models will have a layer of Smart Latex.
Dsi Series models come in several softness options: Firm, Cushion Firm, Plush, Pillow Top, Firm Pillow Top, these will vary in type and thickness of the comfort layers
Some retailers have their "exclusive" collections with minor modification in type and thickness of padding layers. When comparing models always focus on coil type and coil amount, and also presence and thickness of premium materials - memory foam, gel foam, latex. Many retailers will have different names for the same mattress in this line, so you need to focus on an actual line not a single product. To learn more about different names of the same mattress click here.
Luxurious knit cover
High Performance SealyFoam® - firm models
Smart Latex™ - select more expensive models
Posturepedic Titanium Dsi Coil - individually wrapped coils
SitRight™ Edge System - foam encased
of 1 1/2" or greater
The best deals on some Sealy models are available in Costco warehouses or on Costco.com website. If you don't have a warehouse membership you can try to use their advertised prices for a price match with your local store.