Side-by-side mattress testing · 144+ comparisons published
Updated May 2026
Category
King Koil FLOWT
Beautyrest Black C-Class
Comfort
9/10
9/10
Support
8.9/10
9.2/10
Cooling
9.5/10
9.4/10
Edge Support
8.6/10
9.3/10
Motion Isolation
8.8/10
8.9/10
Durability
8.9/10
9.2/10
Value
7.8/10
8.3/10
Quick Specs Comparison
Spec
King Koil FLOWT
Beautyrest Black C-Class
Price (Queen)
$2,999
$2,999
Type
Luxury Hybrid
Hybrid
Firmness
6/10
6/10
Height
14 inches
14.5 inches
Trial
120 nights
100 nights
Warranty
10 years
10 years
Shipping
Free white glove delivery on most orders
Free white glove delivery
Key Advantages
Why Choose King Koil FLOWT
- Spiral coil system keeps lateral airflow open — excellent heat dissipation
- Cooling gel comfort layers stay neutral through the night
- Responsive medium feel suits combination sleepers
Why Choose Beautyrest Black C-Class
- Best cooling in the Black lineup
- Versatile medium-firm feel suits most sleepers
- BlackICE 4.0 + RightTemp foam combo