Specification and editorial comparison · lab measurements not available
Updated October 2026
Category
Beautyrest Black L-Class
Serta iSeries NXG 3500 Hybrid
Comfort
Not lab tested
Not lab tested
Support
Not lab tested
Not lab tested
Cooling
Not lab tested
Not lab tested
Edge Support
Not lab tested
Not lab tested
Motion Isolation
Not lab tested
Not lab tested
Durability
Not lab tested
Not lab tested
Value
Not lab tested
Not lab tested
Blank cells mean that model has not completed our instrumented lab protocol, so we publish no measured score for it. We never estimate a number we have not recorded.
Quick Specs Comparison
Spec
Beautyrest Black L-Class
Serta iSeries NXG 3500 Hybrid
Type
Hybrid
Hybrid
Firmness
8/10
6.5/10
Height
13.75 inches
Varies by comfort level
Shipping
Free white glove delivery
Free shipping
Model specifications are catalog reference details, not instrumented measurements. Confirm the exact configuration and current seller terms.
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 Serta iSeries NXG 3500 Hybrid
- Micro coil layer boosts pressure relief without killing support
- CoolFeel Plus is Serta's strongest cooling package
- Split-head queen and king sizes available