@18-Wheeler/SpeedofSound:
The problem with flash memory is that it doesn't take well to repeated writes of the kind that would be needed in a flight recorder - after a while you end up with bad cells, which is why modern solid-state devices still
AFAIK use hardened IC storage designed for purpose. The issue with flash memory writes is improving with each generation of technology, but I don't think it's reliable enough for aviation use as yet.
Are "most" in agreement that 2hrs is no longer sufficient? I haven't seen anything to that effect, but I wouldn't know where to look. Is there a link handy?
Repeating what I said in my post above, the main issues are not necessarily technical, but legal and regulatory. Leaving MA370 to one side, are there any accidents in recent times where the investigation would have significantly benefitted from more CVR time, let alone offsite storage?