GreenTeam, sorry I hijacked your thread -- didn't mean to! I just ordered a Flobeds and suggest you speak with Dewey or Dave re: your questions, if you haven't already. They provide excellent guidance and don't seem to be about upselling, but rather finding the best fit for the customer. It's in their best interest to do so, since they have a generous exchange policy and seem to rely on word of mouth to bring new customers. They also just seem like decent people who take pride in their work and customer service.
After lots of research, I went with the euroslats. They don't cost much more when purchased with the mattress, and seem to be worth the investment. I also got the wooden legs -- they seem to have engineered the design carefully to ensure stability, etc. and many folks think the wooden legs are a step forward from the traditional metal frames (even though wood beds existed long before metal ones, I think !).
Re the mattress, I erred on the firmer side based again on what others have consistently said (XF + F on one side, F + Med on the other side, with 7-zone on top). I usually read that a talatay/Flobed mattress configuration is softer than expecfted, not firmer.
If you can wait another few wks, I can report back re: any friction issues and the mattress firmness once I've gotten the bed.
