Hi John667.
You are correct that the least “risky” of all options would be to buy something you know and had tested locally, especially if the retailer/manufacturer is knowledgeable, experienced, and is transparent about the type and quality of all the materials and components in their mattresses and who would be able to provide some good guidance and/or has good options and/or suggestions after a purchase to help you make any “fine tuning adjustments” at a nominal cost if your sleeping experience does not quite match showroom testing.
If you cannot find any high quality and value local options, or if they are too costly compared to a directly comparable mattress from an online manufacturer or retailer … then I would consider going in the direction of buying online with the help and guidance of a manufacturer/retailer that you can trust that has your best interests at heart and will help you make your best choice out of the options that they offer. You’ll find that many manufacturers/retailers that are offering online options are moving away from the “one size fits all” products and are offering component style system designs that can be customized to different degrees and/or usually offer some ability to exchange your choices after a purchase at a reasonable cost if it doesn’t turn out quite right as you hoped for. While this is more “risky” because sometimes smaller changes from your “preferred” design can make a bigger difference than people suspect, this risk can be reduced by having a more detailed conversation with the manufacturer who you are considering. If the price difference and your “personal value equation” justifies it though, it would certainly be worth strong consideration.
In your local testing and when assessing any product, also be sure that you find out information listed here so you can compare the quality of the materials and components to the durability guidelines here to make sure there are no lower quality materials or weak links in a mattress that would be a cause for concern relative to the durability and useful life of a mattress before making any purchase.
I look forward to hearing about the results of your local testing and if you narrow down your options to 2-3 choices and can find out the information linked above and post it on the forum then I’d certainly be happy to comment about the quality of the materials
Phoenix