Side-by-side mattress testing · 144+ comparisons published
Updated May 2026
Category
Beautyrest Black L-Class
Black Diamond
Comfort
8.5/10
9/10
Support
9.6/10
8.8/10
Cooling
9/10
9.4/10
Edge Support
9.5/10
8.5/10
Motion Isolation
8.5/10
8.7/10
Durability
9.4/10
9/10
Value
8.4/10
8.2/10
Quick Specs Comparison
Spec
Beautyrest Black L-Class
Black Diamond
Price (Queen)
$2,799
$2,599
Type
Hybrid
Hybrid
Firmness
8/10
5/10
Height
13.75 inches
14"
Trial
100 nights
120 nights
Warranty
10 years
20-year limited
Shipping
Free white glove delivery
Free delivery
Key Advantages
Why Choose Beautyrest Black L-Class
- Firmest model — ideal for back/stomach sleepers
- Highest support rating in the lineup (9.6)
- Excellent for heavier sleepers (250+ lbs)
Why Choose Black Diamond
- Ice Flex Cooling Technology provides outstanding temperature regulation
- Premium hybrid construction with individually wrapped coils for targeted support
- Multiple comfort options (Plush, Medium, Firm) to match your preference