I've been using the KD base for ages, and I find it very good. I can also say that it looks pretty much identical to curry base I've seen a curry-house kitchen (The Zari, in Crawley w.Sussex, about 10 years back when it was the 'Gatwick Tandoori').
In my opinion, in common with many others here, the recipies for individual dishes are 'way off'. I've seen a madras being prepared by a proper chef (same place), and it certainly did not incorporate cumin and garam massala. The chef used chillie powder and a spice mix that looked a lot like many of the mixtures recommneded on this site (those that contain a small amount of 'curry powder' with other spices added). This powder was slighty orangey, not at all like shop bought curry powder (slighty yellowish brown).
My last few batches of madras/vind type curry have been made from KD base, using chillie powder (2tbs), a ready made curry powder from an Asian Grocers called 'Kashmiri Basaar', and a small amount of ground dried fenugreek (methi) leaf. I use one level tbs (15ml) of basaar to 450 mls of base.
The Basaar, by the way, was the suggestion of someone from this site, don't want to appear ungrateful, but I can't remember who, sorry!
I also add a 'shake' (less than 1/4 lev tps) of Worchestshire Sauce (something else the professional chef did), and 1/2 tps cider vinegar.
Result is very good!