Thank you so much for your response. Our “Alpine Plush” mattress is on a foundation that has flex slats which also have tensioners on them. It may be that the mattress hasn’t sagged, but you can notice depressions in the mattress when the bed is made. No matter, we got our money’s worth out of it so I don’t have complaints. The store that sells these mattresses is “no pressure to buy”, the salesman who helped us recently mentioned that we could refit the foundation (for slightly less than 50% of new foundation) and replace the latex layer as you mentioned. All that said if it doesn’t work then it was a waste of time and money. Last night I slept on our blow up bed (which unfolds on a frame) and is tricked out with a memory foam layer and a padded mattress cover. I had it fully inflated to “firm” and couldn’t stand it so let air out of it and actually found it fairly comfortable. But this doesn’t help me understand which mattress to buy! The store that I go to does not offer a trial period so I am reluctant to plunk down $5,000+ for the Berkley Ergo fully latex plush mattress (on a flexible slat foundation). I am glad to hear the you think that the Berkley Ergo mattresses are still making quality products as I haven’t seen any recent reviews of them. As Maverick pointed out, reviews are to be taken with a grain of salt anyway. Berkley Ergo makes a mattress a step up from the “Alpine Plush” that has 3 layers of springs along with the Talay Latex layer and a cover that combines camel hair and cotton. There may also be a layer of wool. I am hesitant to buy any pure latex or memory foam mattress because of feeling too hot. Any more advice? BTW my BMI is 19.4 and my husband’s is 24.4. His side of mattress is firm and mine is sot. Thank you!
Thank you for your response! I did get a response from the European Sleep person who was able to let me know that Berkley Ergonomics still makes quality mattresses. I am going to take the mattress off the bed and remove the Euro slat foundation (it has adjustable slats with tensioners on them, under hips and shoulders) and try sleeping on the mattress without it. I am still confused as to the number of springs etc…that is best for a side sleeper (who has a few vertebrae issues). BTW my BMI is 19.4 and my husband’s is 24.4 ( he indeed does not weight 1 lb!).
It’s all tricky. I think staying away from any all foam structure, regardless of whether it is latex or otherwise is a good idea (the Talalay latex, with a cotton and wool cover, will be cooler and drier than a poly structure, but solid foam is always warmer).
If they replaced the Talalay, and refurbished the slats, shocks and sliders, would they allow you to build the rest of the mattress around that if it didn’t do the trick? The springs should still be good, unless there are obvious splits or separation in the rows. BTW, 5k seems like a lot compared to the prices online, but I could be missing something.
Is there any way to get the mattress on the floor so you can see how much the depression is related to the flexible slats? If it feels clearly better, that could be helpful in making a decision.
It’s a good bet that most of the loss of support is in the slats first, and the latex second. The condition of the cover may be a factor (do not wash it :)).
If you were happy with the mattress, I’m not inclined to recommend a trade up for micro-coils (can be a great feel, but you were happy with what you had), or camel. Camel hair is an amazing fill for a comforter, but I don’t see it doing any favors from underneath, as the finer micron fiber (silk like) is not as resilient as wool. I’ve never tried those though, so who knows (I respect their decision making at BE, and they do not indulge in BS, so maybe there is something I am missing).
Hope that helps. 
It’s funny because Saatva gets very high scores and great reviews in many places, but in Reddit most people passionately hate Saatva mattresses and talk down about them. Gosh I’m still really torn about what to do but my shoulder is still in pain and I’m not sleeping well AT ALL on my Saatva. 
But when I see it get high reviews I think, maybe I just need a talalay topper or something??
At 120 lbs and combo side/back, you likely need something softer on top for pressure relief, but still supportive underneath. If you’re sensitive to sleeping hot and off-gassing, latex can be a good option — it generally sleeps cooler than memory foam. If you go SleepEZ, a soft Talalay over medium Dunlop is usually a safe starting point for your weight. Just make sure your frame has proper slat support (3" or less spacing).
At your weight (120 lbs) and as a side/back combo sleeper, you probably need a softer comfort layer than most “luxury firm” models provide. That could explain the shoulder and hip pain. Latex usually sleeps cooler than memory foam, but it feels more buoyant and less contouring — which some lighter sleepers find too firm. If you go with SleepEZ, a soft Talalay over medium Dunlop could be a good starting point. Also make sure your frame has solid slats (no more than 3” apart), since support underneath really matters.
Thanks, I’m thinking of buying a talalay topper from Sleep EZ first to see how I like it. If i like it I might go for their hybrid or all latex, or one from Ethical Mattress. I just got an adjustable bedframe set up today so will be trying that out. 
So I requested a return of my Saatva mattress and foundation, as I bought an adjustable base. The mattress has felt much better overall with the adjustable base, no doubt, but still hard on my shoulder. Sleep EZ recommended I get the all latex as opposed to the hybrid, and to get the Talalay soft on top, followed by 2 medium dunlop layers or a medium talalay in the middle and firm dunlop on the bottom. Anyone want to weigh in on this? I have to order the new mattress soon, to avoid having no bed when the Saatva is picked up… 
Now I’m worried about returning it and maybe I should just exchange it for the Plush version?? Worried I won’t like latex and will be making the problem worse…or there any other organic mattress companies that make latex-free coil mattresses that would be better suited to my needs as a lightweight side-sleeper? I haven’t really found many, except ones out of my price range.
I’m not sure who or what Sleep EZ is, but I still think a latex/pocketed-coil hybrid would be a great solution for your needs, and likely more affordable than an all-latex option.
I’d still be happy to chat if you’re interested, and answer any questions you have on various options. You can call me directly at 201-618-3565…if I don’t pick up, leave a brief message and I’ll call you back.
Hi DiamondDistinct- do you mind sharing what you ended up doing? I am in a similar situation!
For the frame, grab the KD Frames Nomad (solid hardwood, super supportive, ~$300 on Amazon).
tbh I’m still hunting…I returned the Saatva Classic but now I regret it. It had become tolerable with my adjustable bedframe and a topper, but still hard on my shoulder. It did feel good on my back though. I’m now using a SweetZZZ Honey Hybrid in Medium-soft, but it hurts my lower back and hips BAD. It’s pretty decent on my side, but I notice I usually wake up on my back every morning, and I’m in pain…I’m not sure I sleep as well on my side, but I’m supposed to sleep on my side due to sleep apnea. Not sure how much longer I can manage the medium-soft honey hybrid. It doesn’t support my back enough. If you are purely a side sleeper though, you might like it. There’s a little firmness on my shoulder where sometimes my arm is uncomfortable, but probably if I added my down alternative topper that wouldn’t happen. The mattress seems designed for lightweight SIDE sleepers but less so for combination sleepers. I notice my hips seem to sink in a little too much on my back, and the curve of my back just isn’t correctly aligning to prevent pain.
I don’t know if there’s a good solution…thinking of either trying the medium-firm Honey Hybrid with a SleepEZ talalay topper 2", or using that topper on a Naturepedic coil or hybrid (I can’t remember what it’s called - the cheaper one they sell). I have to post again to see what people think on here…best decision I made though with my adjustable bedframe. Definitely do not regret that one, especially the lovely massage feature!