The 3500 is Serta's premium tier — top of the iSeries NXG Hybrid line short of the flagship 4500. Higher pocketed coil count for finer-grained support, premium CoolFeel™ cover, hand-finished top. This is where the Serta mattress starts feeling really nice. The feel is Medium — the versatile sweet spot most sleepers prefer.Best for: Sleepers ready to invest in a 10-year mattress, anyone who's owned cheaper hybrids and wants the real thing, hot sleepers who need cooling, couples in split-king configurations (Split Head Queen + King available).Comfort: Medium.Sizes: Twin XL, Full, Queen, Split Head Queen, King, Split Head King, Cal King.👋 Compare head-to-head with the Beautyrest Black Series 2 in our St. Cloud showroom — same price tier, totally different feel.Good to know: Every mattress we sell is new and backed by its manufacturer's 10-year warranty. For health reasons, mattresses can't be returned once delivered — so take your time trying them in the showroom, and bring your pillow. Adjustable bases are non-returnable once used. If anything arrives damaged, tell us within 7 days and we'll make it right.The practical stuff: Currently out of stock in the showroom — call or text us and we'll get you a time on the next one. Made to order — order by Sunday for delivery the following week. Delivery: $100 drop-off within 10 miles, $200 with in-home setup out to 40 miles — or free pickup at our St. Cloud showroom.See it in person at Cozy & Rustic, Crossroads Center, 4101 W Division St, St. Cloud — or call or text us at 320-316-2665. Open Mon–Sat 10–8, Sun 11–6. Financing available with Affirm.