It works great and it's very fast.

You swipe your finger from one letter to the next, and the keyboard software identified where you cornered or lingered, and then tries to find the most likely word with letters near those spots.

For example:

This is me swiping "example".

I started on the E, down to X (but I missed and hit C instead), to (past) A, vaguely near M, up to P and L, and then over past E.

The software makes guess about which letters are near a corner or end of my line, and needs to make a word out of those possibilities. It's pretty impressive.