Why use 12v downlights

[Adam W]

Bit what caused the differences? Did it look like that when it was first installed.

If someone has changed the lamps with different types then it is hardly the fault of the lamp is it?

They were all the same type - MR16. Maybe different makes, maybe different transformers, almost certainly different ages, maybe even different wattages, maybe different amounts of pressure, dirt or corrosion on the silly pin connections, and they all look very different.
I've never seen so much variation with GU10s, even halogen ones.
If the end user changes a lamp for a lamp, or a transformer for a transformer, then it's hardly their fault if it all looks different is it? Taking the transformer out of the equation seems a good way of keeping things simple and reducing variation.

 

[Bul]

What kind if elaboration are you looking for?
They are more efficient as you get more lumens per circuit watt
They are more durable as they last longer and can take a bit more rough treatment
And the colour temp speaks for itself, it higher therefore a cleaner/whiter light

I just didn't understand how you get more lumens per watt from 12v lamps, and what is different that they last longer.?
Im all for learning a bit more