My mate has fitted them in his bungalow. 4 in the bathroom, and 15 (yes fifteen) in the living room (about 3m x 4m with a square taken out of the corner for the entrance hall). I have to say, I'm largely with BAS on their aesthetics - but I am impressed with the Halers (which work well with Varilight dimmers which my mate has also fitted).
I think someone else mentioned it, but the Halers H2 are fire rated and sealed to prevent moisture and draughts through the ceiling. They need need covers to keep the insulation off (despite when the electrician told my mate) - but they maintain the integrity of the ceiling you can turning into a bit of swiss cheese ! Most of the GU10 fitting allow air through - and that means in a bathroom they will let damp through into the attic to rot your timbers.
If you do fit standard fittings, they will need to be fitted in a manner that is safe if fitted with 50W halogens even if you only ever intend fitting LEDs - because there is nothing to stop someone coming along later and fitting a halogen.
So against that - 15x7W = 105W, vs 15x50W for halogens = 750W. Switch those on and you can turn off the heating upstairs, though your lecky meter will be whizzing round quite merrily
