On the versatility question, I just made George's Korma (thanks BB for the pointer!) with this base. The results were perfect. Mind you, this Korma recipe calls for no additional spicing to what's already in the base.
So I'm sold on using this Base in the milder dishes as well. Will try a CTM later this week.
Another point about this base is the aroma. I made the base and a Madras with it yesterday, and the house still smells like a BIR, probably better than any other base/curry combo I've tried. In terms of aroma, the Darth Phall was the closest I've got in the past.
Wife's gone for the weekend, so she'll have a nice welcome home ;D
-- Josh