I've now got around to trying this base. It is very orangy in colour, sweet tasting, smooth, creamy and very tomatoey.
I can see why (given it's tomatoiness and other traits) it would (minus the chili) make a good base for a tikka masala.
I also made a chiken madras from it (but from my own recipe rather than SnS's). It was very pleasant and enjoyable but nothing out of this world. It does not compare with a decent BIR madras in terms of depth of flavour and aroma. Probably I'm doing something wrong though

Not a bad base, by any means, but a bit too tomatoey for my liking. But I'm sure many members will be more than happy with it.
I'd be inclined to stick to some other bases on the forum (for me, currently, Bruce Edward's, Ashoka, Infindforu and Darth's).