A couple of times I have enquired at a lighting shop about them and of course read up about them, but the more I learnt, the more confused I became, the main point being do we need new transformers or not to put in LED lights. I concluded it was preferable but not essential. I put it in the too hard basket, and we decided we would do something when one needed replacing. Amazingly the light in each bathroom has lasted 17 years, since the building was new. They are glass covered, so that may make a difference, but they certainly get plenty of use. The two in the kitchen have been replaced, as have their transformers by yours truly.
Now I dislike bits of advertising material falling out of newspapers and magazines, however, one caught my eye. It offered replacement of halogen lights with LED including transformers for $27. In the fine print I noted there was a service fee of $30 if less than ten lamps were replaced.
A phone call to the company and within two days we had the four LEDs installed and we are very happy with them. They are brighter, cooler and use a tiny amount of electricity.
You can pay anywhere between $25 to $70 to have LEDs fitted to replace halogen lights but this scheme is subsided by the government. The company is called Embertec and I recommend it. It also supplied our tv shut down power saving devices a few months ago. They are very professional. The total cost was $140 for the four replacements.