[sfvisser]

Slow transitions are a pain yes, but many UIs without transitions can be a real pain too. Random stuff opening and collapsing without a subtle transition can be really confusing. It’s definitely not just an aesthetic thing.

In my experience somewhere around 150ms hits the sweet spot of not being too annoying and still easy to track the spatial context of what’s going on.

[KennyBlanken]

Android dev tools let you speed up UI animations. Dropping their time to 25% yielded a phone that felt like it had been given a shot of nitro, and I didn't have any trouble using it.

This "easing" crap just makes devices feel slow, and wastes energy and everyone's time.

Stuff that "moves" when you hover over it is stupid anyway - not compatible with touch screens, can't be printed. I've never looked at a site and been anything other than annoyed by stuff that moves/slides/expands.

There's an extra special place in hell for web designers who screw with the page scrolling to make it "better."

[zestyping]

There are some situations where a transition is warranted; they're fairly special and rare situations, but I agree with you when you're talking about "random stuff opening and closing".

In broad terms, if the user cannot predict where things are going to move (typically because the position itself reveals new information, such as the data points in a data visualization), then a transition animation is warranted. On the other hand, if the UI responds to a user command by doing exactly what the user expected (such as expanding the children in an outline list when you click to expand), there is no need for a transition.