Hi kdreams,
When you are down to choices between “good and good” … it’s time for me to step out of the way so that your decision is based on all objective, subjective, and intangible factors that are most important to you.
Both are good quality/value choices although depending on the mattresses you are considering they may also be quite different (you may be comparing all latex with a latex polyfoam hybrid although both of them sell both types (all latex mattresses and latex comfort layers with a polyfoam support core).
My best suggestion is to read some of the many factors that can be involved in your own personal “value equation” in post #46 here, to talk with each manufacturer (Chuck at UD and Ken at AZPM) and then to decide based on which one you are most comfortable with and which one you believe will best meet your objective, subjective, and intangible criteria.
When you are looking at all good options … it would be difficult to make a mistake and you may have to base your decision on your “gut feel” or on some small difference between them that you are most attracted to. If you have questions about either of them … make sure you ask them.
When I bought my last mattress … it took me weeks of agonizing to eliminate some great options and narrow down my five final choices to one … even though probably any of them would have been fine 
Phoenix