Side-by-side mattress testing · 144+ comparisons published
Updated September 2026
Category
Beautyrest Black
Sleep Number i8 Smart Bed
Comfort
9.1/10
8.8/10
Support
9.3/10
8.9/10
Cooling
9/10
8.5/10
Edge Support
9.4/10
8/10
Motion Isolation
8.7/10
9.5/10
Durability
9.2/10
8.3/10
Value
8.4/10
7.5/10
Quick Specs Comparison
Spec
Beautyrest Black
Sleep Number i8 Smart Bed
Price (Queen)
$2,199
$3,099
Type
Hybrid
Air Chamber
Firmness
6.5/10
5/10
Height
14 inches
11 inches
Trial
100 nights
100 nights
Warranty
10 years
15 years
Shipping
Free white glove delivery
In-home delivery
Key Advantages
Why Choose Beautyrest Black
- Exceptional build quality
- Advanced T3 Pocketed Coil system
- BlackICE cooling technology
Why Choose Sleep Number i8 Smart Bed
- Adjustable firmness 0-100
- Dual-zone for couples
- Advanced sleep tracking
Lab Verdict
Beautyrest Black ran measurably cooler in our 60-minute body-heat test (2.9°F surface rise vs. 3.5°F on the Sleep Number i8 Smart Bed). Sleep Number i8 Smart Bed isolated motion better for couples (0.07g vs. 0.1g on the Beautyrest Black). Side sleepers will feel less shoulder pressure on the Beautyrest Black (peak 28 mmHg vs. 31 mmHg). Edge support also favored the Beautyrest Black (1.9" sinkage under 230 lb vs. 2.3"). Responsiveness was comparable; repositioning effort should feel similar on either.
| Metric | Beautyrest Black | Sleep Number i8 Smart Bed | Edge |
|---|---|---|---|
| Cooling (60-min Δ°F) | 2.9°F | 3.5°F | Beautyrest Black |
| Motion isolation (g) | 0.1g | 0.07g | Tie |
| Edge sinkage | 1.9" | 2.3" | Beautyrest Black |
| Shoulder pressure (mmHg) | 28 mmHg | 31 mmHg | Beautyrest Black |
| Response time (s) | 0.6s | 0.6s | Tie |
| Off-gassing | 2 days | 2 days | Tie |
Median of 3 trials, 68°F climate-controlled lab. NL/KW / NL/KW · scoring vv2.1.