It makes me laugh this is called a speed circuit, because it doesn't speed the ball up it slows it down. What is is good for though, it is makes the track a lot more interesting and stops the cat being able to bat the ball around the track in one go, like he can with the completely flat play circuit.
I think if you just had the 'speed circuit' it would be a bit boring because the ball would be stopping all the time and the cat would lose interest. But when you have a few bumps and a flat bit, it makes it more interesting, because every corner has a different amount of force that needs to be applied to the ball to make it go past.
It's pretty easy to put together, a little bit harder to take apart, but okay once you get the hang on it.
The LED ball it comes it is cool, it's quite strobey so it draws a bit more attention to itself than some other LED balls and looks really good at night. The ball is fluorescent yellow and the LEDs are red. It is much smaller than the ball that comes with the play circuit, and hardly weighs anything compared to the non-LED ball. It looks like it has watch batteries inside it, I haven't worked out how to take the batteries out yet, so I don't know if they can be replaced. It feels a bit like I could crack it if I wasn't careful.
I wish it this set had bridge pieces you could get for it like the Bergan Turbo Track, so you could make circuits that cross over each other, that's my only complaint really.
Overall I am happy with it, the cat plays with it on his own and with people too!