[quote]Thank you for the additional information! Because you are both of average weight, it seems even more odd to me that the latex would sag after only 4 years. 10 - 20 years is closer to the average life span for latex.[/quote]
That's what I thought as well, and to be honest it's quite disappointing. I've had a lot of issues with mattresses over the years sagging like this, so after doing extensive research and settling on the Berkley mattress I thought that I finally broke the curse.

[quote]The sag is certainly visible in those images.[/quote]
The sagging is significantly worse on my side (6'1" 200 lbs) than on my spouse's side, if that makes any difference. I tend to sleep hot and my spouse jokes that I melt mattresses 😅.

[quote]The base seems to be adequately supportive as well. If you place the Berkley configuration on the floor is any of this sagging remedied?[/quote]
Not as far as I can tell. The base we have it on does provide a lot of support. The slats do not flex at all when I stand on them with my full weight.

Last year prior to replacing the top layer I believe I performed the "broom stick across the width of the bed and measure the sag" steps to see how bad the sag was and I do not believe it measured anywhere close to what a warranty would cover. The latex seems to have lost its structure and does not provide much support.

Any advice on what I should do next? Silk & Snow is picking up their bed today, so I will be back sleeping on the Berkley until I find a suitable replacement. I'm not sure if it's worth the effort of contacting Berkley about it. But at the same time, I have no idea what bed to look at next. I am tempted to get a bed from Costco, so I can use their warranty and return the bed after a couple years when it starts to degrade, but I would really prefer to just purchase a quality mattress from the start.