Side-by-side mattress testing · 144+ comparisons published
Updated May 2026
Category
Black Diamond
King Koil Xtended Life
Comfort
9/10
8.4/10
Support
8.8/10
9.2/10
Cooling
9.4/10
8.3/10
Edge Support
8.5/10
9.1/10
Motion Isolation
8.7/10
8.4/10
Durability
9/10
9.3/10
Value
8.2/10
8.2/10
Quick Specs Comparison
Spec
Black Diamond
King Koil Xtended Life
Price (Queen)
$2,599
$2,549
Type
Hybrid
Hybrid
Firmness
5/10
7/10
Height
14"
14 inches
Trial
120 nights
120 nights
Warranty
20-year limited
10 years
Shipping
Free delivery
Free shipping through most dealers
Key Advantages
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
Why Choose King Koil Xtended Life
- Excellent support for heavier sleepers and couples over 400 lb combined
- Best edge support in the King Koil lineup
- High-density foams resist body impressions