I was also thinking, since both Standard and Ultra Down cores are put into the exact same casings, shouldn't the Ultra Down look actually fuller (since they have an extra layer) and stretch/ smooth the leather of the casings even nicer than the Standard cores... I know everyone says opposite, Ultra Down causes the leather to look "relaxed", "more rumpled / puddled" but why exactly...?

For those who had a chance to sit on both Standard and Ultra Down - is the difference in comfort significant or minimal? Are Standard ones much harder, both on seats and backs?

If you have Standard ones, how long did it take to break them in? Once broken in, they stay at the same "hardness level"?

Also, when shopping for a fabric sofa a while ago, I noticed that when I sat on a cushion, the sides would often rise quite a bit creating open space between seat cushions. Would this effect be more probable with Standard or Ultra Down cores on a leather sofa, or I shouldn't worry about it with H&M leather piece?

I have to decide on the cores for our Sundance this week and I still have no idea what to do...