Side-by-side mattress testing · 144+ comparisons published
Updated September 2026
Category
Serta iSeries NXG 4500 Ultra Plush Foam
Birch Elite Natural
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
7.8/10
8.5/10
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
Serta iSeries NXG 4500 Ultra Plush Foam
Birch Elite Natural
Price (Queen)
$2,799
$2,812
Type
Memory Foam
Latex Hybrid
Firmness
3.5/10
5/10
Height
Varies by comfort level
13 inches
Trial
120 nights
120 nights
Warranty
10 years
Limited lifetime warranty
Shipping
Free shipping
Free shipping; made to order and assembled in Arizona
Key Advantages
Why Choose Serta iSeries NXG 4500 Ultra Plush Foam
- Genuinely plush — deep shoulder and hip relief
- Best-in-line motion isolation
- Ultimate Edge keeps a plush foam bed from collapsing at the rail
Why Choose Birch Elite Natural
- Three GOLS-certified organic latex layers plus a steel microcoil layer — the most comfort material in the Birch range
- Plush quilted organic cotton Euro top over natural New Zealand wool
- Zoned lumbar support and full perimeter reinforcement in the 8-inch coil base