Having been to both the ‘Big Event’ at the NEC and the One Big Day at Harrogate this year, I think they are worth visiting, mainly so you can ‘test climb’ into and out of the many/various cars on display without having a car dealer hovering over your every move, trying to press you into buying ‘x’ car.
Also, there are generally adapted and automatic cars available to test drive – try getting one of those at a dealership in a lot of cases. The test drives maybe brief but do allow you to ‘rule out’ or ‘rule in’ vehicles to look into further.
My top tip for visiting is know what vehicles you want to test drive (they list them on the ‘one big day’ part of the Motability website) and book the test drives as soon as you get into the event.
If you wait and try to test drive a popular car later in the day, you could be waiting hours for your turn, or even unlucky if all it’s slots are booked.
Incidentally my stock of ball point pens always increases after visiting these event!
Dave