A quick update on how these dishes went. It's really difficult to say I prefer one over the other. Both recipes (slightly modified to include curry powder) produced very enjoyable and moreish dishes eaten with basic rice and a garlic naan. The interesting thing to note is that both were prepared using cuts of meat that clearly were the last choice of other shoppers. The traditional curry cooking process, in particular the pressure cooker, certainly does enhance the characteristics of otherwise difficult cuts of meat.
If anything, all I would say is that they needed slightly more "curry" flavour. What I now intend on doing is reducing the Garam Masala further, trying different blends, increasing the curry powder, and playing around with a few different curry powders and possibly mixed powder or things like Kitchen King Masala. Maybe the addition of a little homemade Balti Paste.
I do hope the OP gives some feedback on there own efforts.