Hi Le Misanthrope,
Welcome to the Mattress Forum! 
One of the attractions of the new breed of “simplified choice” mattresses (see post #3 here) is that they don’t require a lot of time and effort to shop for those that don’t have the time or who don’t wish to test mattresses in local showrooms. Like most factory direct manufacturers or better retailers (locally or online) … there is also no haggling and they provide their best price every day of the year.
Brooklyn Bedding is also one of the members of this site which means that I think very highly of them and that I believe they compete well with the best in the industry in terms of their quality, value, service, and transparency.
[quote]My biggest question is: I’ve only ever slept on traditional spring mattresses. To my knowledge I’ve never slept on any of the foam or latex types. I am really curious how that will be. I have no idea what hardness level I want…but I’ve never thought about it and doubt I’m very picky. I guess that means medium. [/quote].
You can read a little more about latex comfort layers in this article. Latex is a very durable material that is very resilient and supportive compared to other types of foam and in softer versions is also very contouring (pressure relieving). Of course “feel” like taste is very subjective and the most reliable way to know what any material or type of mattress “feels like” to you would be based on your local testing or personal experience but the advantage of this group of mattresses is that they all have a great return policy so you can test it in your bedroom instead of a showroom and the only risk would be the time you spent trying it or in the worst case returning it.
There is also more about the most important parts of the “value” of a mattress purchase in post #13 here that can help you make more meaningful comparisons between mattresses. The BestMattressEver certainly uses high quality and durable materials that would be suitable for any weight range and there are no “weak links” in the mattress and their mattress would certainly be a high quality/value choice.
There is also some good information about their firmness choices on their page here that can help you decide between their different firmness options and if you are still undecided then you can also select the “help me choose” option when you order and they will contact you to give you a firmness recommendation.
I’m looking forward to finding out what you end up deciding.
Phoenix