We retrofitted 40+ halogen downlights some 4 years ago with 240V LED fittings we bought from Bunnings. The halogens had transformers, whereas the LED fittings didn't so that make them very easy to install. They have been incredibly reliable, are cool (very low heat output), and obviously use far less electricity than the halogens.
The GU10 LEDs we bought in bulk pack (Phillips maybe?) from Bunnings as well. They too have been ultra reliable and the light output hasn't changed. In the last three years we have only had maybe four LEDs fail out of 40+.
As a side note, we bought bedside lamps which came with GU10 compact fluorescent globes. They are were pain! They took some time to ramp up full light output, and even that was poor. They have been replaced with LEDs, which are instant on. This is the beauty of GU10. You can put different globes in based on your requirements.
We no longer buy LED globes based on Wattage as watts do not correspond directly with light output. We buy based on Lumen, which is a measure of light output. If you look at different LED globes of the same wattage, they can have startlingly different lumen numbers.
In some situations, such as in the bedroom & bathroom we want it to be brighter, so we opt for the highest lumen output globes available. In the lounge we have more fittings and we are happy with softer lighting, we chose a the more widely available, also cheaper, lower lumen globe.
When choosing globes, you also need to look at the light spread of the globe. Do you want a wide or a narrow beam?
So in summary, LED is preferable to halogen. Chose 240V LED GU10 fittings, and if the fitting doesn't come with a globe select the right LED globe for the situation.