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Beautyrest Harmony Lux Carbon Medium Pillow Top vs Casper The One

Detailed side-by-side comparison — pricing, specs, performance ratings, and our pick.

Beautyrest Harmony Lux Carbon Medium Pillow Top mattress
Beautyrest
Harmony Lux Carbon Medium Pillow Top
$1,149
$1,399 MSRP
Queen
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Casper The One mattress
Casper
The One
$799
$1,149 MSRP
Queen
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Feature
Beautyrest
Harmony Lux Carbon Medium Pillow Top
Casper
The One
Overview
Type
HybridMemory Foam
Firmness
1 = softest, 10 = firmest
5.5 / 106.5 / 10
Queen Price
Current / sale price
$1,149$799
Trial Period
Return window
100 nights100 nights
Warranty
10 years10 years
Performance Ratings
Cooling
Hot sleepers
HighModerate
Motion Isolation
Partners, light sleepers
ExcellentExcellent
Pressure Relief
Hip/shoulder pain
GoodGood
Edge Support
Sit/sleep near edge
GoodFair
Durability
Long-term performance
GoodGood
Compatibility & Features
Adjustable Base
Head/foot elevation
✓ Yes✓ Yes
Split King Support
Two Twin XL per couple
✓ Yes✓ Yes
Dual Comfort Zones
Different firmness per side
Smart Features
App, sensors, auto-adjust
Financing
AffirmAffirm
Materials & Safety
Certifications
Organic / non-toxic
CertiPUR-US, SEAQUALCertiPUR-US
Off-Gassing
New-foam smell concern
CertiPUR-US certified foamCertiPUR-US certified foam
Best For
Ideal sleeper profiles
  • Couples / light sleepers
  • Adjustable base users
  • Organic / non-toxic priority
  • Trial-period conscious shoppers
  • Couples / light sleepers
  • Split King setup
  • Adjustable base users
  • Organic / non-toxic priority
Actions
Our Pick

Need Help Deciding?

For most sleepers, we recommend the Casper The One over the Beautyrest Harmony Lux Carbon Medium Pillow Top. It scores higher in cooling, price-to-value and delivers stronger overall value. The Beautyrest Harmony Lux Carbon Medium Pillow Top is the better choice only if you have a strong preference for that brand's specific feel or design.

Still deciding? Take our 2-minute mattress quiz →

Beautyrest Harmony Lux Carbon Medium Pillow Top vs Casper The One: What Actually Differs

The Beautyrest Harmony Lux Carbon Medium Pillow Top is a hybrid build, while the Casper The One is a memory foam — that single difference drives most of the cooling, motion, and feel decisions below. The Beautyrest Harmony Lux Carbon Medium Pillow Top stands 15.75" tall versus 11" for the Casper The One — a 4.8" gap that matters if you need deep-pocket sheets or are pairing with an adjustable base. The Casper The One is the firmer of the two at 6.5/10 (medium-firm), and the Beautyrest Harmony Lux Carbon Medium Pillow Top sits at 5.5/10 (medium) — a meaningful enough gap that sleeper position and weight should drive the choice. The single largest performance gap is in edge support: the Beautyrest Harmony Lux Carbon Medium Pillow Top rates noticeably higher than the Casper The One, which is the deciding factor if that dimension is high on your list. On a Queen, the Casper The One runs $799 versus $1,149 for the Beautyrest Harmony Lux Carbon Medium Pillow Top — roughly $350 (30%) less, which is enough to factor into the decision unless the pricier model wins clearly on the specs you care about.

Which Is Better For Your Sleep Style?

Side sleepers
Either works

Both rate the same for pressure relief — choose on firmness instead (side sleepers usually prefer the softer of the two: Beautyrest Harmony Lux Carbon Medium Pillow Top at 5.5/10).

Back sleepers
Either works

Both fall in the medium-firm zone back sleepers prefer (5.5/10 vs 6.5/10) — either works.

Stomach sleepers
Casper The One

Firmer at 6.5/10 vs 5.5/10 — stomach sleepers need the extra support to keep the pelvis from sinking and arching the lower back.

Hot sleepers
Spec not available

Cooling rating not available for one or both mattresses — spec not available.

Heavier sleepers (230+ lb)
Beautyrest Harmony Lux Carbon Medium Pillow Top

stronger perimeter / edge support — the two specs heavier sleepers should weight most.

Lighter sleepers (under 150 lb)
Beautyrest Harmony Lux Carbon Medium Pillow Top

Softer at 5.5/10 vs 6.5/10 — lighter sleepers compress less, so they typically need the softer of two options to get proper contouring.

Couples / light sleepers
Either works

Motion isolation rated the same on both — neither has a transfer-disturbance edge.

Price Comparison (Queen)

MattressMSRPCurrentSale?
Casper The One$1,149$799Save $350
Beautyrest Harmony Lux Carbon Medium Pillow Top$1,399$1,149Save $250

The Casper The One is the budget choice at $799$350 less than the Beautyrest Harmony Lux Carbon Medium Pillow Top ($1,149). That's a 30% gap, which is worth weighing against the spec differences before deciding which delivers better value for your situation. Both are currently below MSRP.

Beautyrest Harmony Lux Carbon Medium Pillow Top

Strengths

  • Captured Beautyrest PDP copy published 40% more coils and more pressure-relieving foam than Harmony models
  • InfiniCool Lux adds two layers of active cooling
  • T2 Pocketed Coil system supports motion isolation
  • 100% USA assembled statement was published on the captured manufacturer page

Considerations

  • Beautyrest now redirects the product URL to the mattress collection page
  • Inventory should be treated as clearance/legacy rather than current core assortment
  • Split King and Split King Dual were not sold on the captured manufacturer PDP

Casper The One

Strengths

  • Three-layer foam build with Casper Core support
  • Strong motion isolation for an all-foam bed
  • Split King is sold from the PDP

Considerations

  • No coil edge feel
  • No active Snow cooling package
  • Medium-firm feel is less plush than Cloud One

Who Should Buy Which?

Choose the Beautyrest Harmony Lux Carbon Medium Pillow Top if you…

  • Sitting near the edge
  • Organic / non-toxic priority shoppers
Check Beautyrest Price ↗

Choose the Casper The One if you…

  • Hot sleepers
  • Budget-conscious shoppers
Check Casper Price ↗

Beautyrest Harmony Lux Carbon Medium Pillow Top

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