I've used this site in many personal projects. Very nice and easy to find what you're looking for.

Is there something I'm missing here? Why wouldn't a larger app take longer to install?

Install rate is referring to the percentage of users who install the app at all, versus those who choose not to because the app is too big.

I think "rate" refers to install rate, as in how many users install the app, not install speed.

Maybe they're far worse to you..

You also have the option of creating something yourself if everyting sucks so much.