Difference between GZ10 and GU10??

[webstarblue]

When my inlaws moved into a new apartment, some of the bulbs had gone in the kitchen and bathroom. I spoke to the electrical company who fitted the buildings and they told me to use a GZ10 in the bathroom and a GU10 in the kitchen, as the GU10 will not last as long in a steamy atmosphere of a bathroom. I know there is a difference between them and the way they dissipate the heat. But why should one type go into the kitchen and the other in the bathroom? The reason I ask is because I have just been into a lighting shop and asked for a GZ10 and was offered a GU10 in its place. I said no thanks as its a Gz10 I want, I had 5 assistants telling me they are the same except the chamfering near the fitting is different. I stood my ground and said they are different bulbs but they wouldnt have it. What do you reckon.

 

[Spark123]

Wiring matters article
In a nutshell, you can fit both GZ10 (dichroic) and GU10 (aluminised) lamps into GZ10 fittings but only GU10 (aluminised) lamps into GU10 fittings.

 

[webstarblue]

Wiring matters article
In a nutshell, you can fit both GZ10 (dichroic) and GU10 (aluminised) lamps into GZ10 fittings but only GU10 (aluminised) lamps into GU10 fittings.

Yes I realise that, but why should the GZ10 be used in a bathroom?