Hi Bingley,
You can see the more detailed specs of the Beautiful in post #2 here.
An innerspring has a different subjective “feel” than latex but “soreness” has more to do with the specific design of a mattress and it’s suitability for your specific needs and preferences in terms of PPP (Posture and alignment, pressure relief, and Personal preferences) than it does with the type of materials or components in the mattress. All materials and components (including innersprings, polyfoam, or latex support layers) have both softer and firmer versions and the type of soreness (lower back pain is a common example) that comes from alignment issues is generally because the primary support layers are too soft (whether they are an innerspring or latex or polyfoam) or the comfort layers are too thick and soft and allow the heavier parts of the body (primarily the pelvis) to sink down too far before they are “stopped” by the firmer support layers.
The Beautiful has a firm support core (36 ILD) which is suitable for most people but the comfort layers are very thick and soft (6" of softer talalay latex) which may be too much “softness” for those who are heavier or who sleep on their back or especially their stomach. The more subjective “feel” of a mattress in a showroom will often not translate well into real life long term experience (see this study which indicates that in some cases the odds of success with testing based on “feel” alone are less than random chance) and it’s important to make sure your testing is as careful and objective as possible (along the lines of the testing guidelines in post #1 here) so it has a better chance of predicting your long term experience on a mattress.
Pure Latex Bliss are usually (depending on the prices that you actually end up paying) tend to be better quality and value than most mainstream choices but are not in the same value range in terms of material value compared to many smaller manufacturers across the country or that are sold online which may have a lower cost for the same type and amount of materials. Material value though doesn’t take into account the suitability of a mattress and it’s design or any of the other parts of a successful mattress purchase which may be an important part of each person’s “personal value equation” because no matter what the quality or material value of a mattress if it isn’t suitable for your specific needs and preferences then it would have little value to you.
If another mattress has the same type of materials in the same firmness levels and layer thickness then it would be very comparable in terms of how it feels and performs but when you are comparing two different mattresses then every difference in design can be cumulative and result in a mattress that feels and performs very differently even if the actual materials are the same. You can read more about trying to “match” one mattress to another in post #2 here but in general it’s more effective to assess each mattress on it’s own merits because it’s not as likely that another mattress will have exactly the same design. There may also be other mattresses where the “net effect” of all the differences cancel each other out and for you it may feel very similar to another mattress with a very different design (even though it may not feel the same for someone else with a different body type, sleeping style, or perceptions).
In most cases trying to match another mattress is a matter of personal side by side testing (as close together in time as possible) or if you are considering an online purchase then more detailed discussions with an online retailer or manufacturer that is familiar with the mattress you are trying to approximate of with mattresses that have a similar design.
The adjustable bed thread here may be helpful 
I don’t know what brand or model they were referring to and PLB doesn’t sell adjustable beds to my knowledge (although many of their dealers may sell adjustable beds of one brand or another in addition to their mattresses). A site search also didn’t show any listings on their site for adjustable mattresses. I would consider a mattress purchase and an adjustable bed purchase separately so that you have the chance to choose each individually because an adjustable bed is much easier to choose based on specs without individual testing because they all have similar options and features available that don’t really require personal testing like a mattress (unless for example you want to compare some of the features such as the “feel” or strength of the massage features in which case most of the better known brands and models are widely available).
Phoenix