We replaced most of our scummy downlights with the Lons 4000K from Lighting Direct. If you buy them on special (which they have nearly as often as Briscoes) it works out about $30 each including driver. They are the exact same size as the existing downlights, so it takes <10 minutes per light to swap them in.
We haven't tried the dimmable ones, but the ones we have are great. We've had them for about 6 months now in the lounge and no problems or colour shift as yet, and these would have the most use of any in the house. Wife likes the 4000K, its a bright sunny day white, I installed them in the garage and at one point later that week rushed down to find out why the garage door was open when it wasn't.


