Hi Lizabeth,
I would “echo” dwzemens’ comments about the Tuft & Needle. While they may be a great “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) … they aren’t a memory foam mattress and don’t contain any memory foam.
The Tuft & Needle would be a good quality/value choice but the top 3" comfort layer is a high performance 2.8 lb polyfoam that would be very different from memory foam and is in a different category completely. There is more about the Tuft & Needle in posts #2 and #6 here.
While the only way to know for certain whether any mattress will be a good “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) will be based on your own personal experience … one of the attractions of the “one choice fits all” style of mattresses is that they simplify the buying and decision making process which can be very attractive to some people and may be one of the most important parts of their “personal value equation”. With any retailer or manufacturer that only offers a single mattress though you will find that they will be the “best” match for a relatively small percentage of the population, a “good” match for a larger percentage, an “OK” match for a larger percentage yet, and for those that it isn’t a “good enough” match … they also have a great return policy that lets you start all over again with choosing another mattress with little risk outside of the time you spent trying the mattress or returning it.
Having said all that … and assuming that you decide to pull the trigger on your purchase … congratulations on your new mattress 
I hope you have the chance to add your comments and feedback to the forum when you’ve received it and have had the chance to sleep on it for a bit.
Phoenix