Hi Nycmattress,
While I can’t help with what to choose … hopefully I can provide some information that can help you with “how” to choose between your two finalists and the retailers you are considering.
There is more about the pros and cons of a local purchase vs an online purchase in this topic and the additional posts it links to in post #4 of the topic.
There is also more about the most important parts of the “value” of a mattress purchase in post #13 here which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability and PPP (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists (based on all the parts of your personal value equation that are most important to you).
If you test a local mattress that is a good “match” for you in terms of PPP (Posture and alignment, PRessure relief, and your Personal preferences) and you are using that as a guideline or reference point for an online purchase that isn’t exactly the same mattress it can be somewhat risky because the type, thickness, and firmness of every layer and component in a mattress will have some affect the feel and performance of every other layer and the mattress “as a whole” so in some cases some seemingly small differences in design between two different mattresses can make a surprisingly meaningful difference in how they compare in terms of PPP.
On the other hand if you are comparing two mattresses that are exactly the same then the risk of an online purchase would be reduced because your local testing would apply to both mattresses equally and in this case some of the other parts of your personal value equation (such as differences in price including any shipping or delivery costs, differences in return/exchange policies and the costs involved, and your own personal preferences and how you feel about supporting a local business vs buying online) would all become more important parts of your personal value equation if you are looking at exactly the same mattress and the only difference is where you purchase it.
If these are the two finalists that you are deciding between then you really have two decisions to make. The first is which of the two mattresses would be the best "match for you in terms of PPP, durability, and all the other parts of your personal value equation that are important to you. Both of the mattresses use high quality materials and there are no weak links in either of them and there would be no durability issues with either of them so it will really come down to which one you believe you would sleep best on based on your local testing along with the guidance of the retailers you are dealing with. There is more about how a latex support core vs an innerspring support core compare to each other in post #28 here but this would be a preference choice more than a “better/worse” choice so the most reliable way to decide between them is based on your own local testing. You can read more about microcoils in this article and in post #8 here and post #2 here but these are also very durable components so the choice between comfort layers that use microcoils vs comfort layers that use latex would also be a preference choice more than a “better/worse” choice.
Once you have decided on which of the two mattresses you wish to purchase then you would have your second decision which is where to purchase it. If your final choice is the BE mattress then there are two of the members of the site that sell Berkeley Ergonomics mattress in the NYC area (Scott Jordan and Urban Natural) and I believe that both of them carry the mattress you are considering so you may want to talk with both of them. TMASC is Canadian so they can’t sell the BE mattress to US customers so they wouldn’t be a realistic option for you with this mattress.
If you decide that the Obasan will be your final choice then I believe that TMASC is allowed to ship these into the US so you would need to call them to find out what your costs will be after any exchange or delivery costs to see what the difference in prices and of course there would also be a difference in the process and costs involved with any exchange as well between a local retailer or a retailer that was in a different country if an exchange were to become necessary.
Once you are confident that all your finalists would be a good match for both of you in terms of PPP (or you have good exchange/return options after a purchase if you aren’t) and that there are no weak links in any of them in terms of durability (which there aren’t) then you would be down to finalists that are comparing “good to good”. If there are no clear winners between them at this point (which is usually a good indication that you have done some very good research) then you are in the fortunate position that any of them would likely make a good quality/value choice and post #2 here can help you make a final choice based on your local testing or mattresses you have slept well on, your more detailed conversations with each of them, your confidence about PPP and the suitability of each one, their prices, your preferences, the options you have after a purchase to fine tune the mattress or exchange or return the mattress or individual layers, any additional extras that are part of each purchase, and on “informed best judgement” based on all the other objective, subjective, and intangible parts of your personal value equation that are most important to you. Sometimes your final choice may even come down to some very small differences that are just a matter of “gut feel” or “educated best judgement”.
You are certainly looking at two very high quality choices.
Phoenix