knex amusement park models

[flatmouse]

Hoping that someone has experience of these and can guide me towards the best one?
Was really looking at the first four, although research shows many more.
Am torn between giving "first of the series" ie the ferris wheel, or the potentially more exciting "rollercoaster".
For a 7 yr old boy.

What are your thoughts please?

I have seen the roller coaster set up in a shop and it looked great, dd1 has asked her grandad for either the wheel or roller coaster for x-mas but i'm not sure if it will be a bit tricky for her to put together (she's almost 6) so she might just be getting a big tub of knex instead.

I would go for the roller coaster.

Thanks :-)
Was leaning towards roller coaster but it is hard to tell without physically seeing them set up.

There are vidoes of them set up and running on Youtube