Picky as in having above average expectations? Yes. Picky as in discarding stuff because of minor issues? Nope.You're just being picky, now, aren't you?
Example regarding opera: I cannot read parts of the UI!!! with my OS-colorscheme. Bright text on bright background just isn't very efficient.
Regarding k-meleon: The bookmarks-sidebar is the most frequently UI-element that i use when browsing. And it being incompatible with my keyboard layout means, that if for example i want to enter an umlaut somewhere, it instead erases the textcontents of the inputfield!