Hi voyager39, and welcome back after almost a year!
As you probably already have read, any mattress you choose will be unique to you based on your Stats (height, BMI, sleeping position(s) and any underlying health conditions) and your PPP (Posture & alignment, Pressure relief, and Personal preferences). Without knowing your Stats, it’s difficult to assess how either the BB Plank or Winkbed will be compatible for you in support or comfort.
I bought a Plank mattress in 2020 and have been sleeping on it for two and half years. Recently, the sag level in the mattress has made the unit painful to sleep on, so I’m now seeking a replacement. I notice that other members have reported the same problem.
Sorry to hear of your Plank mattress ‘sagging’ after 2 years; as you say, this is unfortunately not uncommon as you can read here. Possibly the HD support foam has insufficient density for its thickness…the specifications listed on their website do not quite match what was provided to a forum member in august 2022 for the Plank Firm; we do suggest any foam in a potential mattress has no more than an inch or so of lower grade foams (for memory foam no lower than 4 lbs/cuft for normal range weights, and 5lbs/cuft for higher range weights) and if polyfoam is used, with at least 1.8 lbs/cuft density, just to ensure you have support. A higher BMI sleeper with a foam of insufficient density would likely see premature wear, for example
Winkbed is new to me, so I’m interested in hearing from people who are sleeping on this mattress brand now, particularly people who purchased the firmest possible Winkbed model
As the Winkbed is a hybrid with very little detail or transparency on the density or thickness of their components, it is also difficult to assess how this may perform for any consumer. Winkbeds is also shipped compressed, which can possibly prematurely wear some of the components depending on how long and in what environment the compressed mattress is stored.
One option for me is to ask BB whether they’d consider a pro-rata credit for the mattress I now own, since my experience indicates that it does not maintain its advertised status as the firmest mattress in the U.S. for anywhere its warranty period of ten years. I’ve no idea whether this will work or not.
I would be surprised if BB would agree to the pro-rated credit…but there’s nothing lost in trying! If you want to provide your Stats, we may be able to further assess the WinkBed and how it may work for you; also, hopefully other forum members can chime in with their own experiences with these mattresses.