Hi Christine,
Either you are getting some misinformation here or there has been some kind of misunderstanding because there is no such thing as latex that is made from soy. If the Talalay is a blend then it would be about 70% synthetic rubber and 30% natural rubber and if it’s 100% natural Talalay then there would be no synthetic rubber in the foam. There is more about the different types and blends of latex in post #6 here.
If the latex is Talalay then it would be either Latex International or Radium and if it’s made in the US then it would be Latex International.
If it’s Dunlop Latex on the other hand I would want to know the blend of natural/synthetic but it could be made in many countries. There are two Dunlop manufacturers in the US who both make continuous pour Dunlop (one only makes a synthetic/natural blend and the other makes anything from 100% synthetic to 100% natural) but most of the 100% natural Dunlop latex you will see would be made either in Sri Lanka or in India and it’s not likely it would come from China (they don’t export much Dunlop latex to North America).
I can only speak to the quality of the materials and if all the materials in a mattress are either Talalay (either blended or 100% natural) or 100% natural Dunlop then it would certainly be good quality and there would be no weak links in the mattress.
Outside of durability though … there are too many unknowns, variables, and preferences involved for anyone else to know whether a mattress is a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) and you would either need to use careful and objective testing to assess this or if you can’t test a mattress in person then you would need to make a choice based on a more detailed conversation with a knowledgeable and experienced retailer or manufacturer (see mattress firmness/comfort levels in post #2 here) that can help you decide which of their options is likely to be the best match for you.
You can read more about the smell of rubber in post #2 here. In most cases it will reduce to levels that are either fine or undetectable for most people in a few weeks or less although there are occasional exceptions and some batches where a stronger smell can last longer. Some people may also be more sensitive and for them it may take longer for the smell to reach a level that they either don’t notice or that it isn’t an issue.
Phoenix