I bought one of those some years back (microsoft arc). I found the feel /shape when using the mouse seemed a little off, and it's lack of a functional scroll wheel was very annoying. Though it has thousands of positive reviews on Amazon; looks like some people do like it even with the $50-70 price tag.

I bought instead a "slim" (their name) jelly comb mouse for $11, and it works great. Doesn't even take up much more room since it is slightly fatter but more compact.

But the arc mouse does look really cool.

Although a bunch of studies found 25 hours or even much longer (median 25 hours), with a lot of variability from person to person, another later study suggested that early ones found so much variability due to residual light contamination and that the length was closer to 24.2 hours

Ensuring complete darkness for the duration of the study, they also found less variability from person to person.

There are also studies showing how much light is needed to change your circadian rhythm to a shorter or longer or different (think jet lag) cycle.