Hi ahoward,
Most of your questions will be answered in the tutorial post here which has all the basic information, steps, and guidelines you will need to make the best possible choices … and know how to avoid the worse ones.
I’m always happy to make some comments about the quality of the materials in a mattress and to help you identify any weak links or make more meaningful quality/value comparisons between them but any “comfort” differences or differences in PPP (Posture and alignment, Pressure relief, and Personal preferences) between them would be too subjective and the mattresses are too different from each other to be able to compare them outside of your own personal side by side testing or sleeping experience (or a more detailed conversation with a manufacturer or retailer that had personal experience with both of them).
There is more information and a very detailed analysis of the Saatva mattresses in post #1 here that may be helpful. A forum search on Saatva (you can just click this) will bring up more information and feedback about them as well.
The Maidenmaine/Daley Bros website list the layers of the Luxury as follows (from bottom to top) …
660 MIRA-COIL™ Spring Unit 15 Ga. Coil Wire
Heavy Duty Comfortlast Fiber Insulator Pad
Highly Resilient 2.6 Lb. High Density Foam
Specially Treated Cotton Felt for Comfort And Fire Resistance
Inner Tufted Construction
2.6 Lb. 27 ILD HR Convoluted Foam
Damask Cover Quilted To 3/4" of Soft Resilient Foam and another layer 3/8"foam
The Mira-Coil innerspring is a continuous coil and is different from the Bonnell Spring used in the Saatva (there is more about the different types of springs in this article and in post #10 here) but both are lower cost innersprings. Having said that … the innerspring of a mattress isn’t generally the weak link of a mattress in terms of durability (the upper or comfort layers will soften or break down faster than the deeper support layers or components) so either one can make a good choice in a mattress as long as the rest of the materials and the mattress design overall is suitable for you in terms of PPP.
Outside of any differences in the innersprings and how that affects the feel and performance of the mattress (based on your testing) … the Maidenmaine luxury uses very high quality and durable foams in the comfort layers (2.6 lb polyfoam which is much higher quality than you will generally find in a mainstream mattress) and there are no weak links in the design or in terms of durability. It certainly appears to be a good quality/value choice that would be well worth considering although the “value” of any mattress purchase will depend on the parts of your personal value equation that are most important to you. Of course you would still need to do some careful and objective testing (hopefully using the testing guidelines in the tutorial post) to make sure it’s a good match for you in terms of PPP because no matter what the quality or value of a mattress if it’s not a suitable match for your body type, sleeping positions, and personal preferences and you don’t sleep well on it it would have little value to you.
Some of the better options or “possibilities” I’m aware of in Maine are in post #2 here.
Phoenix