Ergonomics, and not just the UI, are much more important compared to how often they are discussed. Every camera system feels different to every photographer. No one sets out to make an uncomfortable system - it must feel good to *someone*. But feel in the hand often matters more than the huge number of parameters we discuss here on an hourly basis (MP, DR, and corner sharpness leap to mind). Weight (balance), feel in the hand, ease of changing lenses (I could not get a grip on X1D lenses to save my life. Did they HAVE to make the surface near the mount perfectly smooth? Every other bit rotates!). These matter much more, but can't be quantified (ok, weight, sure, but not balance).
I never fell in love with either the H system or the X1D from an in-the-hand point of view, but others do, and that's what's important.
Matt