Ubuntu Wonderful?

These seem to be mostly Kubuntu related - I use Kubuntu myself and like it, but it's likely
that Kubuntu upgrades aren't so widely tested or fixed.  Ubuntu certainly seems to be a bit
more polished, though I prefer Kubuntu generally.

I think it's also a question of priorities - an upgrade bug that breaks someone's wireless
card or other hardware is much more serious than (from one of your examples) something that
breaks Konqueror, particularly if there's a simple-ish workaround.  All upgrade bugs should be
fixed, but there's only so much development time available, so I guess the Ubuntu/Kubuntu
teams focus on the most critical bugs.