There's some useful info in this thread, and the one it links to:

http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=8245&page=1

I've been using some based on 24-27 of the so called 5050 form factor LEDs. Lumen output circa 380-450 Lumens. Warm white. Various sources on ebay and amazon.

Main thing to note is the much wider beam angle some LEDs have - so although they produce a lot of light it can sometimes be spread out over a larger area making it look less bright when you test one on it's own. When you replace a whole room full (eg a grid of 3x3 or 4x5 etc) this effect dissapears as the light from one overlaps with others. I recon my kitchen is actually brighter with 400Lumen LEDs than with 50W 230V GU10 halogen.

Only question I have is over the lifetime. They do need to last if they are to save money. It's believed the main cause of failure might turn out to be the electronics not the LEDs themselves - so in theory 12V LEDs with seperate transformers might last longer than 230V GU10s with built in "transformers".

I'd been looking at 3 new fittings for my kitchen, to replace 3 existing MR16 50W ones. I want to re-cycle these old fittings a new project so my thought was to buy new kitchen fittings. I saw some dimmable 9W FR rated ones at £35 each but the diodes appeared to be part of the whole fitting, and not as a replaceable lamp. I am unsure now whether to buy simple comparatively cheap GU10 housings and the lamps separately or to go for the full integrated fitting. The 9W dimmable Cree lamps I mentioned in the OP are 480-580lm.

<blockquote><cite>Posted By: GaryB
These sound like commercial fittings.

Are they from a reputable manufacturer who will still be in business 5 or more years from now? What happens if one of the 3 fittings fails prematurely, after a few years - will you have to replace all 3 to have a matching set?

Personally, I would only go for fittings which can be relamped.


Yes, they were commercial fittings Gary and your point about suppliers is true. Also true is the fact that LED technology is moving ahead so fast that todays LED GU10s for example may well be "burned out " as Damon alludes, by the time they have reached anywhere near their advertised life. Which makes a bit of a mockery of the whole energy/cost saving aspect. Maybe back to the drawing board and another look at CFL GU10s although they are not exactly flavour of the moment.