The other half had a mini years ago and I had one of the original one in the 80’s. Both had central speedo’s and I don’t remember it being a problem, just brain training of where to glance.
IF I feel like I am too old to learn how to modify my eye movements I will certainly give one a try, for £30 if I don’t like it, I’ll mount it in the back and any rear seat passengers can see how fast we are going.
I think these could be handy if they change between kph and mph if you are travelling in a different country.
This brings me onto another question does the ‘proper” dash speedo have the facility to change between the two ??