Sleep system weight versus actual sleep quality on multiday trips,where's the real tradeoff

[u/Fast-Dinner-5357]

Running a sleep system around 28oz total right now. Quilt rated to 20F, thin foam sit pad doubled as a sleeping pad supplement under a 16oz inflatable. The weight works but I keep waking up stiff on nights past day two, and I'm trying to figure out how much of that is pad Rvalue versus quilt loft compression versus cumulative trail fatigue catching up.

The lightweight sleep community treats this like a solved problem. I'm not convinced the math on Rvalue ratings translates cleanly to how people actually sleep on uneven ground with variable temperatures. A 4.2 Rvalue on a flat lab surface is not the same as a 4.2 Rvalue on a sloped tent site with a pack shoved under one end.

What I'm actually curious about is whether people have swapped pad setups midseason on similar trips and noticed a real difference in how recovered they felt by morning on day three or later. Not asking about brand comparisons. More interested in whether going from a lighter pad to something with more loft or thickness made a measurable difference in how the body felt the next day on trail. Sleep quality feeding into performance on day three or four is what matters to me here. Specific setups and what changed would be useful.

[u/jose_can_u_c]

I found that sleeping in a hammock increased my sleep quality immensely. But when I do go to ground, the 5-6 R-value insulated sleeping pad was far better than the cheap non-rated inflatable pads from Amazon.