A few months ago I tried some of the LED Hut dimmable GU10's

http://ledhut.co.uk///new-4-5-watt-gu10-cob-bulb-wide-beam-angle.html

I knew my "old" dimmer wouldn't be suitable for the low power of LEDs,
so also bought an MK trailing edge, LED specific dimmer

http://www.mkelectric.com/en-gb/Products/WD/logicplus/LED%20Dimmer/Pages/K1523WHILV.aspx

The combination did *not* work satisfactorily, the dimmer was noisy and
reduced the maximum brightness of the LEDs, the LEDs flickered as you
operated the dimmer knob and the dimmer would sometimes go into
'lockout' mode where it cut the brightness to minimum until powered off
and back on, the above symptoms stopped if one of the LEDs was replaced
with an old halogen lamp.

So the dimmer was sent back, and I rewired the light fitting so that the
lamps could be switched in combination 0/2/3/5 from a two-gang switch so
I had some control over lighting levels.

Now I'm doing the lounge, and I *really* want to keep a dimmer in there,
and ideally the 75W halogen will get swapped out for an LED fitting.

So I noticed that Varilight make a dimmer module that fits the MK Grid
Plus system

http://www.tlc-direct.co.uk/Products/VLGJP400MK.html

I bought one, together with a grid yoke, front plate and a couple of
2-way switch modules to control other lights within the room, I've been
gradually replacing the old Volex light fittings with MK Logic Plus, so
the Grid Plus matches those pretty well.

The bits arrived today, just tried the new dimmer back on the on the
same set of LEDs I used before - and it's chalk and cheese -
smooth/silent dimming, no flikering, didn't even have to go into the
leading/trailing config of the dimmer.

The same dimmer is specified to work with electronic transformers for
dimming of 12V LEDs too, I bought one varilight transformer on the same
order just to give that a try out, but not tried it that way yet.

Anyway, V-pro LED dimmer ... recommended!