Hi rgd53,
From a quality point of view both of these use good quality materials and there are no “weak links” in either of them.
From a “value” point of view … most mattresses made by the same manufacturer and sold at the same retailer would have similar value across the lineup based on the cost of the materials and components. The main difference is in the support layer where one uses mostly latex which is a more costly material and the other uses polyfoam.
You can read a little more about some of the differences between an all latex mattress (and I would put the Lady Lark in this category in spite of the 2" polyfoam layer on the bottom) and a latex/polyfoam hybrid (such as the Gold Leaf) in post #2 here.
The Lady Lark would certainly be “worth it” based on the quality and cost of the materials themselves (latex is a higher quality material even than good quality polyfoam) but whether it is worth it to you personally would depend on your own personal testing and on any differences that you feel between them and whether you preferred one mattress over another in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences). Each person’s perceptions, preferences, and Personal value equation may be very different from the next and the criteria and tradeoffs that are most important for each person can vary widely.
Phoenix
PS: You had a duplicate post so I switched them both to the same thread.