In my younger years ... I was used to sleeping on something firm ... like the ground or a horsehair mattress on plywood
... but nowadays in my ah ... advanced age ... I prefer abit more comfort ... and the 4" memory/firm combo mattress (from Overstock.com) over the Froli system is by far the most luxurious I have ever had.
Even more luxurious is the fact ... that it was all crafted for me while I was away on a business trip to Vegas ... including the fitted sheet(s) neatly sewn so that it is easy to slip over the V ...
I believe the mattress was $109 (free shipping
from Overstock) and the Froli system was from Craig's list (with more than enough to also do the aft berth)